Category Archives: Genomics & Genes

Genetic Differences in Kidney Cancer? So What or What’s UP?

A few years back, I attended a kidney cancer conference with a highly eminent kidney cancer doctor.  He opened his talk by saying he was no longer treating kidney cancer!  The room was stunned, patients already wondering where to go for the next appointment when he finished his statement. “From now on, I will be treating cancers of the kidney.”

Not a small distinction, and a great way to confuse the patient and the newly diagnosed, but is critical.

Just because some growth lands in the kidney, that growth is not the same person to person, and even not from kidney to kidney in one person. In the link below, CURE magazine, May 5, 2017,  interviews Dr. Marston Linehan who expands upon the history and future of this work, which I have used as the basis for this report.  This research started in the 1980s, when doctors and researchers noted that some families were at greater risk l to develop some growths and tumor, some of which ‘landed’ in the kidney.  The early work defined that disease, Von Hippel Lindau hereditary cancer syndrome as to its genesis–an inherited mutational tendency in the VHL gene.

http://www.curetoday.com/articles/expert-stresses-significance-of-genetic-differences-in-kidney-cancer

This research started in the 1980s, when doctors and researchers noted that some families were at greater risk l to develop some growths and tumor, some of which ‘landed’ in the kidney.  The early work defined that disease, Von Hippel Lindau hereditary cancer syndrome as to its genesis–an inherited mutational tendency in the VHL gene.  Given that clue, patients with kidney cancer but from this inherited tendency, most often had mutations in that same gene.  These were ‘sporadic’, out of the blue mutations, but that opened the door to treatment improvements.  About 90% of patients with the more common clear cell kidney cancer have a mutation in the VHL gene–but not due to any inherited tendency.  Much work has been done for these patients and less for those with the rarer cancers of the kidney.

AND…there are more inherited kidney cancers which also enlightened research.  One is PRCC, Papillary Renal Cell Carcinoma, defined in the 1990s.  The gene that drove this kidney cancer was MET, wh0se mutations make those patients “highly likely to develop bilateral, multifocal, Type I papillary kidney cancer,” per Dr. Marston Linehan of the National Cancer Institute.

Research is being done for these people, as well as those who are affected by the similar disease which is NOT inherited. There disease also comes from sporadic mutations, these from the same MET gene.  This work is critical, as the generally available treatments are not as effective with the rare RCCs.

Still another and challenging rare kidney cancer is HLRCC, or hereditary leiomyomatosis with renal cell carcinoma. Linehan says it is not uncommon, and can make the patient vulnerable to develop leiomyomas–particular kinds of growths–and an aggressive form of Type 2 papillary kidney cancer.  Quite different genes make this happen, which can be referred to as Krebs cyle enzyme mutation cancers.  Obviously, still quite different that the garden-variety clear cell RCC (ccRCC) and requiring quite a different approach as to treatment.

Though there are currently studies underway to find more appropriate therapies for these rarer forms of RCC, some with combinations of agents that have been developed earlier in the decade, and with agents that were not originally envisioned to be used with kidney cancer–oops, cancers of the kidney.

If you don’t really know the pathology of your tumor and its genetic drive, you don’t have a complete diagnosis.  And if you relatively young for kidney cancer, the 46 and under group, this is time to discuss it with your kidney cancer cancer of the kidney specialist.

PS According to Linehan, there are at least 13 different types of inherited kidney cancers, and at least 16 known genes that can cause cancer in the kidneys…lots to learn and to discuss with your doctors!

 

 

 

 

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Immune Therapies: Headlines, Hype or Hope?

Recent headlines called a new medication, Nivolumab, both a miracle or breakthrough and more.  Is it hype or hope?Why is it so hard to sort out the reality?

Let’s go through the facts from the New England Journal of Medicine and ignore the headlines. First, its being  in the NEJM is important, as it has passed review by other researchers.  (Sadly missing in too many ‘breakthroughs”).

The new med, Nivolumab was compared against Everolimus, a second-line treatment. Therefore Evero is thought to be of lesser effectiveness than the first line meds.  Second-line meds are generally used when others meds quit helping or their side effects are too hard. Automatically NOT the miracle cure, but another option when first-line treatments fail.

Should Nivo have been compared to the first-line meds?  Being better in the first-line would be bigger deal, but we need more approved meds. Second-line treatments usually are easier to ‘beat’, as the new med must be better or less toxic.  Again, more likely to be approved!

PATIENT CHARACTERISTICS

The study had 821 patients 24 countries, half using Nivo and half Evero. Patients were similar, 90% having had a nephrectomy, removing the tumor and some or all the kidney. Then the cancer spread, making metastases, (mets, for short). These patients had 1-3 treatments, first-line drugs like Sutent, a targeted therapy, and a few had used cytokines or even chemotherapy.  Having had an mTOR inhibitor like Everolimus was not acceptable. Most had lung mets (67%), followed by liver(12%) and then bone mets (18%). Most with 2 or more sites of mets.

To enter the trial, the patient had to have had disease progression after their last treatment, within six months of enrolling in the trial. No doubt, some patients had greater disease progression than others, but had relatively good performance status, not completely bed-ridden or unable to function.

The median time from initial diagnosis of kidney cancer at any stage to entering the trial was 31 months;  half had been diagnosed less than 31 months ago, and half more than 31 months before the trial. That range of time from diagnosis to trial was 1 to 392 months. That means that for some patients, they went a long time either fighting the disease since diagnosis, having a later recurrence, being treated, yet having disease progression years after the intial diagnosis.  At least one person was diagnosed 392 months earlier. This is a good reminder to patients who have been told, “I got it all”. This darn stuff can return, so having a plan B is important. Again, the previous treatment failed and these patients got directed into this trial.

GENERAL RESULTS

Median Overall Survival (OS) is a measured when one-half of the total number in the group dies. Median OS for Nivo was 25 months with some patients still surviving at time of report, beyond the 25 months. For Evero, OS was 19.6 months, some of who were also likely surviving, as well.  The OS of 25 months was clearly better with the Nivo group by this analysis. Nevertheless, half of all the 821 patients total died while on this trial from progressive disease.  Of  183 of the 410 Nivo patients, 183 has died by 25 months, and 215 of the 411 Evero patients had died at 19.6 months. 

 

There is no report of ongoing response here, but many went on to other meds, as explained below. 

Median Progression Free Survival (PFS), measurable growth of disease,  was 4.6 months for Nivo, 4.4 months for Evero.  The median shows that half of each group, roughly 200 each had return of disease in less than 5 months!  Again, these trial patients were pretty sick or at risk. All had been treated earlier, and had to stop previous treatments due to recurrence of disease. However, this shows a pretty quick return of disease or new growth from the base CT scan for nearly  65-70% of all patients.

One subgroup did a bit better than the 4 1/2 months median PFS.  At six months after the start of treatment, there was a special subgroup was noted,  about 1/3 of those patients–145 pts (35%) with Nivo, and 129 (31%) with Evero. Obviously they did not die or have Progressive Disease until after six months.  The Nivo group had eventually had a median PFS of 15.6months, and the Evero group, 11.7 months.  Their success pushed the median OS higher, especially for the Nivo group.

Obviously, there were some patients with far more aggressive disease in both groups, some dying before six months, and others not progressing to more disease until after six months.  In contrast, nearly 1/3 of all the patients had PFS of 12-15 months, and much longer OS. What is the common characteristic in the most successful two groups in both arms of treatment?  Not answered by this trial report.

The duration of treatment was longer with Nivo, and likely easier to tolerate. Since Nivo was given by IV every two weeks, the doses were most consistently received. Even so, 51% of them had dose delays, but no per dose reductions.  Those people were seen by the medical team every two weeks.

The Evero group took oral meds, and 66% had dose delays or interruptions with 26% with at least one dose reduction. This would indicate that these meds could be hard to take, or perhaps lacking the same interaction with their medical team.  Of course the Evero patients may have underreported how much of the medication they actually took!

However, the reported types of side effects were generally similar, but the more severe grade 3 and 4s effects in the Evero group.There were 2 treatment related deaths in the Ever group, none in the Nivo group.

POST PROGRESSIVE DISEASE

Even after the disease did progress, about half of  patients in both groups stayed with their meds–despite ‘failing’, the researchers hopes that would continue to benefit, perhaps slowing the disease.  In a local clinic setting or with a less experienced docs, their meds might have been stopped or changed. Afterall, those meds were no longer “working” and  mets are growing. This approach is significant to consider, especially after multiple treatments.  (The decision to keep giving a medication or increasing its dosage where tolerable is causing some changes in treatment in a number of the targeted therapies.)

Perhaps because of being in a trial or getting care than was more expert than most, one-half of  patients chose to keep on the trial meds.  Others crossed over to the med in the other arm or returned to existing non-trial meds. In some countries, there were likely fewer choices than in the US.  There are no real stats as to survival for those on those who stopped taking the meds. It is reported that indicate that 55% of the surviving Nivo group and surviving 63% of the Evero group went on to other agents. About one-quarter of the Nivo group shifted to  the Evero. Of the Nivo group, 36% shifted to axitinib.

Sadly, as per the chart in the New England Journal of Medicine, all these patients had died by 30-33 months post enrollment.  However, it is again not clear what was effect, if any on that period from the non-trial drugs.  Of the 227 who stopped Nivo for any reason, nearly half shifted to Evero. Of those who stopped Evero, 140 went to Axitinib.

DURABLE RESPONSES?  HOW LONG? FOR HOW MANY?

The writers of the study say that there was a higher number of objective responses with Nivo vs Everolimus, and that many (of the Nivo group) “were durable”.  There is no definition of ‘durable’.  My question is “What equals durable?”.  We patients really want a cure, but are very grateful for anything that pushes the cancer back, slows it, stops in from growing any further. Nevertheless, we do want those responses to last.  The clearest reference to durable responses is a note that 32 of the Nivo patients and 6 of the Evero patients had a response that lasted more than 12 months.  But in an unexplained statement, the median duration of treatment was just 5.5 months for the Nivo patients, 3.7 for the Evero group.  It seems that there was not an extension available, or that the patients moved on to a different treatment or passed away.

CONCLUSIONS AND EDITORIALIZING AGAIN

It seems that Nivo is more helpful for some patients than others in this group previously been treated with other TKIs. This is NOT A SILVER BULLET.  There would be greater value to know more about the molecular nature of  the tumors of the responding and the non-responding patients.  We desperately need to know for whom any of these drugs is likely to be more effective.  The headlines that don’t discuss that challenge underserve us, as does the design of the trial that does not elicit the more nuanced, genomic data that could be forthcoming!

We all know that headline claims are more wonderful  than the reality.  The story of RCC medication development is that of more and more help in a difficult disease, making mixed progress, while the other researchers find out that RCC is really many diseases.  Clear cell is probably better defined as being made up of four types, Papillary Type 1 and Type 2 being further divided into three Type 2, then there is chromophobe, clear cell papillary and the really odd versions of RCC.  I known this, and so do you.  But why don’t the researchers incorporate those definitions and monitor the patients with those various subtypes as they go forward?

Good luck to all of us.

 

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Classifying Kidney Cancer by Its Biology; Good Looks Won’t Do It Anymore

Looks don’t matter in kidney cancer as much as they used to, as more information comes to us about the molecular or biological nature of the diseases which fall under the “kidney cancer” umbrella.  Can those important biological differences be seen in the pathology laboratory? Must we rely on next generation sequencing to determine which of the subtypes we might have?

Recent work by Dr. James Brugarolas and colleagues is reassuring.  Even as they found  new subtypes of clear cell renal cell carcinoma, they have also determined that these differences can be seen the pathology lab.

Why is this important?  So-called similar tumors may behave in quite different and more aggressive ways, so this is vital to understand the threat of recurrence from a very small tumor.  The affects monitoring and eventually will be helpful in drug selection.

An interview at the 13th International Kidney Cancer Symposium   October 2014

https://www.youtube.com/watch?v=tCoLwClv0tw

Cut and paste the above youtube address into your browser to be able to hear the lecture, while following along below.  The questions are in bold face.

Dr. James Brugarolas Discusses Biologically Classifying Kidney Cancer

“What we have learned with the development of next generation sequencing (NGS) is that no two tumors are the same. Every tumor has different mutations. Mutations are the drivers of tumor biology. With the advances of next generation sequencing, we have been able to identify and group different subtypes of kidney cancer, according to their mutation status.

Specifically, my laboratory discovered that the BAP1 gene is inactivated in 15% of clear-cell renal cell carcinomas. We found that BAP1 mutations are associated with high nuclear grade. That let us to hypothesize that patients who had BAP1 deficient tumors are going to have more aggressive tumors.

Furthermore, we found that mutations in BAP1 tended to anti-correlate with mutations in the second gene discovered by the Sanger Institute, by Michael Estrada and Andrew Futreal, the polybromo1 gene, PBRM1.

That led us to a classification that about 50% of the patients with clear-cell renal cell carcinoma will have PBRM1 deficient tumors and 15% of patients will have BAP1 deficient tumors. A small percentage of patients will have tumors that are deficient for both genes.

In a very productive collaboration we have had with Mayo Clinic, with Rick Joseph and Alex Parker, we’ve been able to determine that these different subtypes are associated with very different outcomes in patients. Patients that have tumors which are competent (not deficient) for both BAP1 and PBRM1 have excellent survival, whereas the cancer specific survival (CSS) is very poor in patients that have tumors that are deficient for both BAP1 and PBRM1. BAP1 deficient tumors have a somewhat intermediate survival phenotype, and the PBRM1 deficient tumors are similar to tumors that are competent for both BAP1 and PBRM1.

So we think for the first time, we’ve able to identify subtypes of clear-cell renal cell carcinoma that are likely to inform therapy in the future.

There is a gap between the discovery of the gene, to the determination of the clinical implications and subsequently to the therapeutic developments. That is because the therapeutic developments are going to emerge from the biologic understanding which we don’t have yet.

   How can improved classification of kidney cancer subtypes improve clinical trial design?

 That’s actually a very good question. So, what has traditionally happened is that a trial may be performed and one may find a group of patients–sometimes small, sometimes larger–that appear to do well with that agent. But if the group of patients is small, the trial is considered to be negative and the drug is abandoned. And I would say the problem is not that the drug did not have activity, it is that we were not able to identify the group of patients who appeared to benefit from that agent.

So the classification that we have developed and the identification of these different subtypes will pave the way to be able to do correlations. So then, when a clinical trial is executed when it is able to characterize better those subsets of patients that may benefit from the agent. For instance, as I was alluding to before, the BAP1 gene is inactivated in 15% of the tumors. It is possible that one of the drugs which has been tried in kidney cancer could have activity against that tumor. But there could never be a trial in that is positive that is being active in a small percentage of the patients, in 15% of the patients.

By identifying meaningful biological subtypes, we hope to deconvolute kidney cancer. It probably makes sense in trials going forward to do prespecified analysis of these genes that we now define as different biological subtypes–to be able to get at the question whether a particular treatment is having greater affect in one biological subtype versus the other. It is possible that it may not be that not all the PBRM1 deficient tumors that benefit, that are inhibited by a particular agent, there are other mutations. But it’s the beginning that which will lead us to identify those biomarkers and patients who are most resistant to a particular treatment.

 What is the significance of improved disease classification for kidney cancer patients?

 That is also an excellent question. These are discoveries that we and others have made over the last two or three years. The implications clinically have begun to be unraveled. It’s going to take significant effort and investment in research for us to go forward. We need to understand how loss of these genes, how mutations in BAP1 and PBRM1, are affecting processes inside the cancer cell, leading to kidney cancer development.

And in particular, we need to understand how BAP1, which is associated with most aggressive type of kidney cancer, is inducing that process. How is it that loss of the BAP1 gene makes the tumor be so aggressive? It’s only once we are able to elucidate the signaling pathways, that we will be able to identify targets for therapeutic invention.

On the other hand, we already know that for patients with localized disease, their prognosis is influenced biology of the tumor. I was alluding to this before, those patients who have removal of a tumor, localized to the kidney who deficient for BAP1 and PBRM1, they have a very high likelihood of recurrence in a short period of time. Those patients whose tumors are wild type for PBRM1 and BAP1 can do very well. (Wild type here means that the two genes are competent, or not deficient.)

Importantly, from the important view of translating these findings to the clinic, we have been able to develop assays, immunohistochemistry assays which are routinely performed in tumor samples at most institutions. (This is done in pathology labs).That allows us to very quickly determine whether we are dealing with the wild type tumor, BAP1 tumor, PBRM1 deficient tumor, or one that is deficient for both.

(Transcribed from the above YouTube video by Peggy Zuckerman. Any mistakes are mine alone, but hope this is helpful in understanding this approach to using gene sequencing in kidney cancer.

May 16, 2015)

 

 

 

 

 

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Clear Cell RCC: Not as Clear as It Used to Be!

We struggle to understand what to do about our kidney cancer, but first must  exactly WHICH kidney cancer we have. Frankly, even the doctors are never too sure, and outcomes for patients with the “same” cancer varied widely.  No ready explanation was available, in those bad old days.

Treatment decisions were easy, but not effective for most, when every kidney cancer patient was treated the same.  Patients had surgery and were sent home. Those with smaller tumors, under about 2 inches, had little or no follow up.  Those with larger tumors might be monitored more frequently. Mets might emerge, and maybe more surgery would follow, but no meds were available until 1992 when high dose interleukin was approved.

Patients who presented with metastatic disease were not even offered surgery, being told that there no value to removing the primary!  An ongoing “controversy” was whether there was value in a nephrectomy when mets were found.  Too bad, so sad. (If your doctor is telling you that last bit, you need a new doctor. Now.)

Then came the recognition that there were different kidney cancers, variants and subtypes, all based on the look under the microscope.  Conventional kidney cancer became known at clear cell, and a mix of new subtypes were named.  We now hear of clear cell, papillary type I and type II, chromophobe and more.  Sarcomatoid RCC can arise from any of these types, confusing things and reflecting a more aggressive course for the patient.  Most are sporadic, out of the blue, but others have an inherited component.  Again, making things trickier yet!

Ironically, the trials in the late 80s of high dose interleukin which led to the first FDA-approved treatment, included all the above types. The relatively low response rate in this trial may have been due to the rarer RCC types, unlikely to respond.  This minimized the use of HD IL2, perhaps to the detriment of many patients. The targeted therapy studies often excluded the rarer types, hoping to boost response in a more limited group.  Few trials really test agents appropriate for the non-clear cell types, so the guessing game for them is really the norm.

With that background, there was still wide variation in the outcomes for clear cell RCC patients.  Some patients with small tumors, found at an early stage, can have very poor response to treatment.  Many such patients have long-term survival, easily over 10 years, while others who “seem” similar, succumb to their disease quickly.

Why is this the case?  Short term survival vs long term survival, aggressive appearance of mets vs slow-growing, good response to treatment vs minimal response?  Why would the same disease be so different?

Easy answer.  It is not the same disease.  Clear cell RCC, that so-called conventional type, maybe 75% of all the kidney cancers, is not really one disease. Clear cell may be subdivided into four separate types, each with its own survival pattern–and all due to its early genetic drivers. Researchers have been able to sort out the genes, compare the mutations, deficient or over-expressed, and find them in tumors of patients who were treated and followed over many years.

Just as there is no magic bullet, no one medicine that fixes everything, there also seems to be no one poison bullet.  It is not just one thing that goes wrong, one nasty gene breaking the DNA rules, but a combination.  And there will be more combinations.  This is like the typical disaster stories, where it is not just one thing that goes wrong, but a series of events and changes.  Each one of the series might not create a problem, but in combination and with the right timing, there is a perfect storm–the very aggressive tumor.

Without getting too technical, clear cell RCCs can have a mix of genes that mutate.  Recent studies have shown that two genes in particular, BAP1 and PBRM1 can either be sufficient (or competent or positive) or they can be deficient in their expression.  There are four possible combinations, positive for both genes BAP1 + and PBRM1+, negative for both genes BAP1- and PBRM-, and combinations with the BAP1+ and PBRM-, and the reverse, BAP- and PBRM+.

Why does this matter for the study patients? All of them had localized disease at the time they were diagnosed and all were clear cell patients of similar age.  BAP1 was mutated/inactivated/deficient in about 15% of these patients, and that mutation was associated with high nuclear grade, or a more aggressive type of tumor.

About 50% of clear cell patients had the PBRM1- tumors. Others had a mix of one gene positive and the other negative. Mutations of BAP1- and PBRM1- were rarely found together, but that combination predicted poor survival, in one study of just 2.1 years.   Having just the BAP1- had an overall survival of 4.6 years median, while the deficiency of PBRM1 (-) had an overall survival of 10.6 years.

This shows that clear cell RCC is really not one disease type, but four.  Most importantly for patients is the knowledge that these varying mutations may respond to different medications.  Also, these mutational differences can be seen in immunohistochemical or pathology tests, which can give greater guidance to treating physicians.

Coming soon is another lectures by Dr. Brugarolas, so watch this space.

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Younger Patients & Kidney Cancer: Your Genes or Your Luck?

Once you reach a ‘certain’ age, you are horrified, but not surprised to get a cancer diagnosis, or hear about it in a loved one.  That same cancer in a young person is even more horrifying, we instinctively know.

Most kidney cancers (and there are more types than we previously knew) are found in people in their 60s and 70s.  Bad enough, but a cancer called by the same name and found in a younger person is often a very different cancer, with a very different prognosis.

Some new research recognizes that special attention should be paid to those RCCs found in patients 46 years of age and younger.  Why is this?

The quick answer is that this may represent a more aggressive kidney cancer and/or be of a familial or hereditary nature.  That important distinction has researchers strongly recommending that young patients be referred for genetic testing.  This can explain those special risks and create more appropriate treatment plans, and alert other family members as to special monitoring. Critically it may change the approach to any removal of the kidney and/or tumor.

Typically a small renal mass might be monitored or removed by either surgery or some laser ablation.  If removed, the tumor can be assessed by a pathologist–a look under the microscope.Without a prior biopsy, the ablated tumor will not be examined, and no genetic testing can be done.

BIG HOWEVER HERE: even with a good pathology report, that may tell only what that tumor looks like–not what pushed it to grow, i.e., the genetic drivers. And those genes don’t go away with the tumor, so the risk remains that more tumors will grow, maybe in the second kidney, or in the partially removed kidney.  Plus the rest that can happen with cancer…

An 75 year old whose small renal mass is removed will likely function well with one kidney.  That same tumor  in a 35 year old creates another challenge.  If that tumor is driven by familial genes–not just by sheer bad luck–more tumors on the other kidney may be in the works.  A partial nephrectomy   must be considered. The risk of more tumors emerging in that kidney AND the other kidney is high.  The younger patient needs decades of good kidney functioning, but those decades carry the risk of the emergence of more mets.

What else should trigger a genetic testing?

Quick answer: anything that doesn’t look like the senior  citizen with a single tumor in one kidney.  More officially below:

Early onset of kidney cancer is 46 years or less.

Bilateral (two-sided) or Multifocal (many locations) kidney tumors

Family history of kidney cancer, 1 or more close relative, 2 or more in more distant relatives

Kidney cancer with either a mix of other tumor types roughly related to kidney cancer or with lung cysts or pneumothorax (air leaking out of lung into chest cavity)

Personal or family history of kidney cancer syndromes.

The above list is from Yale  School of Medicine, Professor Brian Shuch, who work includes dealing with heredity forms of kidney cancer.

More small renal masses found at an earlier age in more patients, as our imaging techniques improve and more CTs scans are done. Not all will be hereditary, and many will be sporadic or out-of-the-blue kidney cancers.  Those are likely due to the sheer chance. Things go wrong as trillions of cells divide and make DNA mistakes along the way. Years of environmental damage may overwhelm the body’s ability to correct those DNA mistakes–i.e., the immune system gets overwhelmed, tricked, tired, etc.

Kidney cancer found at an early age or with the bilateral/multifocal tumors simply must be tested as to it genetic origins.  This gives information critical to protect the rest of the kidney(s) and to participate in treatment that is more helpful.  Finding an effective treatment will still be a challenge, but proper treatment requires knowing exactly which kidney cancer you have.  From there, a real plan can be developed.

Just as I remind all readers to work with an experienced RCC oncologist–not just a surgeon and/or urologist (sorry guys, we need a team)–those who fall into this early and hereditary renal cell carcinoma category must also work with super specialists.

The person to contact at NIH is genetic counselor Lindsay Middelton at (301) 402-7911. She is with the National Cancer Institute’s Urologic Oncology Branch.  An introductory link is below to the NCI and two other rare kidney cancer organizations.

http://www.cancer.gov/cancertopics/causes-prevention/genetics/genetic-testing-fact-sheet

Birt-Hogg-Dubé syndrome:
http://www.bhdsyndrome.org/for-families/what-is-bhd/

Other syndromes causing kidney cancer:
http://www.bhdsyndrome.org/for-families/kidney/other-causes-of-hereditary-kidney-cancer/

 

 

 

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Genetics of Renal Cell Carcinoma: Paving the Way for the Next Generation of Therapies

Why don’t the various medications work better for RCC?  Why do some patients do well, and others so poorly?  Why is it so hard to choose the right medicine?

This lecture explains why patients  and doctors must play the guessing game in treatment. It may be the most important lecture in this blog, and provides an explanation as to why RCC cancers behave so differently, even those variants  with similar pathologies. (My notes are in italics, like this, added to help with this complex discussion…I hope.)

Presented by Dr. James Brugolas, MD, PhD.: Kidney Cancer Program Leader Associate Professor of Internal Medicine & Developmental Biology; University of Texas Southwestern Medical Center

http://www.chemotherapyfoundationsymposium.org/mobile/player.php?id=476

“I am going to talk to you today about the genetics of kidney cancer and how I believe it is paving the way for the next generation therapies. There are no significant disclosures.Brug 1 What is the ProblemWhat is the problem? This is a problem that we are well aware of some nowadays. We’re using one drug for all patients with kidney cancer.   You may imagine that these are all patients with metastatic renal cell carcinoma. But it is a heterogeneous population. Some have the red tumor, some of them the green tumor, and the drug may work with a subset of patients, but it may not work for another subset of patients.(Left half of the slide with the meds not reaching the patients with GREEN tumors.)

We should be evolving to a paradigm where patients with different tumors are treated with different drugs. (Right half of slide shows Drugs A and B going to different subsets of patients.)BRUG 2 Kidney Cancer subtypesIn the context of renal neoplasms , as you are well aware, we have kidney cancer with clear-cell carcinoma which accounts for the vast majority (75%) of that, and that’s going to be the focus of the first part of the talk.

BRUG 2 EDITSCaptureThe work from the Sanger Institute by Andy Futeral and Michael Stratton led to the identification of mutations in the PolyBromo1 gene. Polybromo1, like VHL, the most commonly mutated gene in clear cell renal cell carcinoma, is a two-hit tumor suppressor gene. That means both copies are mutated in tumors. They identified through truncating mutations in approximately 41% of clear-cell RCC. PolyBromo1 encodes BAF 180, which is a component of a nucleosome modeling complex which may regulate, among other processes, transcription.” (Peg & Wikipedia say that transcription is the first step of gene expression, where DNA is copied into RNA, giving instructions. Pretty basic cell info.)

BRUG 3BAP1 loss defiens new class of RCCCapture

“Work from my laboratory led to the discovery of another gene mutated in RCC, the BAP1 (BRACA1 associated protein-1) gene. Like the BPRM1 and VHL, BAP1 is a two-hit tumor suppressor gene, but it is mutated in only about 15% of sporadic clear-cell RCCs.

This work was done focusing on tumors that were of high grade. Indeed, we found there was a correlation between BAP1 loss and high grade, and also activation of the mTOR1 pathway. BAP1 encodes a nuclear deubiquitinase. Of greatest interest, mutations in BAP1 and BPMR1, we found, are largely mutually exclusive. This is shown this more detailed the next slide.

BRUG 4Mutation in BAP1 ^ PBMR1 mut excluWhat you are seeing here are 176 tumors, each in a row. These are tumors that have a deletion in PBMR1, these are tumors with the insertion, this with a point mutation (referencing the various symbols P). All the tumors in blue are tumors that have a mutation. As you can see most of the tumors, we see with PBRM1 mutations do not have mutations in BAP1. (Column 4 has many BAP1 mutations.)

(in last column) Here you have some tumors with mutations in BAP1, and we only identified three tumors that had mutations in both genes. (Very end of column 4) The probability of having mutations in both genes was statistically significant. Based on the individual mutation probability, we would have expected 13 tumors to have both genes. Only three were found, suggesting that BAP1 and BPRM1 mutations are largely mutually exclusive.

BRUG 5BAP1 & PBRM1 meta analWe went on to performing a meta-analysis. This is looking at data from that Beijing Genome Institute, at Memorial Sloan-Kettering and this from the TCGA (The Cancer Genome Atlas). As you can see, even though the numbers are small, the numbers of tumors with mutations in both BAP1 and PBRM1 was reduced, compared to the expected number of tumors based on the individual mutation frequency, and the p value was statistically significant.BRUG 6BAP1 & PBRM1 gene signatureI’m going to go through these and not spend much time, but suffice it to say that that we found that these tumors that have had mutations in BAP1 have a characteristic gene expression signature, and the tumors that have mutations in PBRM1 also have a characteristic gene expression signature. These gene expression signatures do not overlap. These are tumors that have different gene expression patterns and different biology.  (Per Peg: this shows that these are biologically different tumors. Notice the different patterns of red and blue below.)

BRUG 7 BAP1 & PBRM1 ex  diff SMALL

We think this establishes a foundation for the first molecular genetic classification clear-cell RCC. In our series, 55% have mutations in PBRM1, and 15% of the tumors have BAP1, and including 3% have mutations in both.  (The balance are wt, wild-type, meaning as it occurred in nature, not mutated.) BRUG 8Fdn Mole Gene sign ccRCC We also observed that there is a statistically significant correlation between mutations in BAP1 and high grade (tumors), and mutations in PBRM1 in low-grade (tumors).

So that let us to propose the following model. This is a model based on the fact that, very interestingly, VHL, BAP1, and PBRM1 are all located on chromosome 3. In fact, the short-arm of chromosome 3, and this is an area that is deleted in the majority of patients with von Hippel-Lindau-associated renal cell carcinoma, as well as in the majority of sporadic renal cell carcinoma, depicted here in blue.  (VHL associated RCC is an inherited type of RCC, not arising from a mutation…but along the same chromosome.)

BRUG 9  BAP1 & PBRM1 on chromo 3p VHLYou can imagine that with a single deletion, the kidney cell is losing, in fact, four copies or one copy of these four different tumor suppressor genes, the BAP1, PBRM1 and VHL.BRUG 10 VHL mutat high low grade diff

We have proposed the following model. We believe that renal cell carcinoma, and this is consistent with data from Gerlinger and colleagues, that it begins with an intergenic mutation in the VHL gene. And this is followed by loss of 3p, with a concomitant loss of one copy of all of these tumor suppressor genes. We then think that a mutation in PBRM1 leads to the loss of PBRM1 function, which is a two-hit tumor suppressor gene and low-grade tumors, whereas the mutation in BAP1 is associated with the development of high grade tumors.

REFER to ABOVE PIE CHART re High and Low Grades

This model also predicts that patients with BAP1 and PBRM1 deficient tumors may have different outcomes. So we simply took those patients whose tumors we had analyzed and asked what happens to their outcomes. (The UTSW and TCGA cohorts reference tumors from different institutions. Blue lines are the PBRM1 deficient tumors, and red lines the BAP1 tumors. The lines which fall the quickest show poorer overall survival.)BRUG 12 BAP1 & PBRM1 diff outcomesAs you can see here (LEFT), we found that patients with PBRM1 deficient tumors had a significant better Overall Survival than those who had BAP1 in their tumors, which had a Hazard Ratio for that of 2.7.

We did a similar analysis with the TCGA cohort, and we found (RIGHT) essentially the same result in the same hazard ratio of 2.8, indicating that BAP1 mutant tumors are associated with worse outcomes in patients. This data has now been reproduced by Hakimi and James Ying at Memorial Sloan Kettering, as well as the TCGA with their own analysis and our colleagues in Japan and Tim Eisen.

BRUG 12 Limit of SequencingThere are some limitations of sequencing. We all like next generation sequencing, but it has some limitations. First, it focuses on DNA. Secondly, it uses pooled material. Thirdly, it has reduced sensitivity which is a consequence of contamination by normal cells. In addition, a negative result does not guarantee that there is normal function. There is poor discrimination of subclonal mutations in different cell populations. So as a consequence of using poor material, we cannot tell whether these mutations are found in the same cells or different cells. Typically, it involves fresh frozen samples which are reduced in numbers, and consequently has limited power for doing some analysis.

Interestingly enough, immunohistochemistry (IHC), which we’ve use for a long time is a lot more precise. This is because actually you get information at the cellular level, and you get information about the protein. I mentioned to you that BAP1 is a two-hit tumor suppressor gene, which basically means when it gets mutated, you lose both copies.BRUG 14 dev of BAP1 IHC testAs you can see here–this is the same series showed before. These are here in blue the tumors that had mutations, in the second column, you can see blue and brown, the results by immunohistochemistry. That is done by IHC. And BAP1 is a nuclear protein, as you can see in these beautiful nuclear staining.

The bottom line is the majority of tumors that had mutations (referencing blue column data points) had lost BAP1. There were two tumors with point mutations where we were able to detect the protein. But there were three additional tumors we could not detect protein, but where there was no protein. If there is no protein, there cannot be functioning.

The rest of the tumors, with one exception, were all positive. So compared to mutation analysis, in fact, there is positive predictive value is better and the negative predictive value is pretty similar.

BRUG 15BAP1 loss assc w red CSS ccRCC

We have used this immunohistochemisty test in conjunction with the Mayo Clinic, looking at their registry with over 1300 with localized ccRCC. As you can see, looking here with people with specific RCC survival, patients with RCC tumors that have BAP1 positive tumors have significantly better survival outcomes than those who have BAP1 negative tumors, again with a Hazard Ratio of approximately 3.

BRUG 16Evalu of PBRM1 by IHC cohortNow in the same cohort we looked at BPRM1, which like BAP1 in a two-hit tumor suppressor gene, and we find no significant differences.Brug 14Now in the same cohort we looked at BPRM1, which like BAP1 in a two-hit tumor suppressor gene, and we find no significant differences.

Importantly, this test allows us to identify tumors that are simultaneously mutated for BAP1 and PBRM1. This is important.BRUG 17a IHC ids tumors UpperSlide A                                                                                                 Slide B  

(This slide in presented in two parts to help understand lecture.)
Upper half of slide showing stained pathology images.)

I am going to show you look at this tumor over here (upper left path image A) you can see that the tumor cells, there are some that have brown nuclei, but these are the endothelial and the stromal cells (along the edge of the white). The tumor cells are negative for BAP1.

This is the immunohistochemistry (upper right path  image B) for PBRM1, where we find the same thing,where the tumor cells are negative for PBRM1.

BRUG 17b IHC PathSLIDESlide C                                                                                                                  Slide D

Now (left path image C) compare these tumors with these images below. You can see here that the tumor cells positive for BAP1 in this area (the upper right corner of the path image C) and they are negative (in the lower left corner of Slide C), where you can see specific nuclei which look blue over there.

Now if you look at the parallel section (Lower right path slide D) you can see the area that was BAP1 positive (left hand side???D) is actually also PBRM1 negative, and the area which was BAP1 negative is actually PBRM1 positive.

So what you have over here (in the upper slides A & B) is a tumor which has lost BAP1 and PBRM1 in the same tumor region, the same cells. The tumor has lost BAP1 and PBRM1 in independent regions. Obviously these tumors will be acting differently and the tumor we are most interested in is this tumor type (in the upper left image A).

BRUG 18 IHC BAP1 & PBRM1 ids 4 sutypes ccRCCSlide should include quote “BAP1 and PBRM1 do NOT predict outcomes independently of SSIGN”

You have seen in our immunohistochemistry test. We believe we can separate clear cell renal cell carcinoma into four different molecular subtypes. This is looking at Mayo registries, where the patients with best outcomes are those whose tumors are well-typed for PBRM1 and BAP1. Then you have 2) patients that have tumors which are deficient for PBRM1, 3) patients that have tumors that are deficient for BAP1, and 4) patients whose tumors are deficient for both. As you can see the Hazard Ratio is 1.3, 3.2 and 5.2, respectively.

As I mentioned to you at the outset, that these tumors were underrepresented and indeed in this very large cohort, we found a very large significant underrepresentation with 1.8% of the tumors being double mutant, compared to 5.3% (which would been expected) with a very highly significant p value, again indicating there is mutual exclusivity–for reasons we do not yet understand.

Importantly BAP1 and PBMR 1do not predict outcomes independently of SSIGN. SSIGN is the nomogram created by the Mayo Clinic, which is based on Stage, SIze, Grade, and Necrosis. This is the SSIGN nomogram; this is the independent validation. You can see the curves separate beautifully, depending upon the score.

BRUG 19 Nomogr vs BiologyBRUG 20 Nomo vs Bio ANIMACapture

Now another question I submit to you. Should nomograms trump biology? In other words, if they live the same, “What do I care?” That has been the traditionally the thinking in the clinic. But look at these animals. A bullfrog and a grizzly bear also live about 30 years. However, they’re very different. The same is true for cottonmouth, a beaver or hummingbird or a newt. So even though they live the same, they are actually quite different!

We should be probing deeper and in fact, they should be dealt with differently!

BRUG 21ccRCC per genes

I believe that clear-cell renal cell carcinomas are in fact divided for at least four different subtypes. There are tumors that are wild type for both BAP1 and PBRM1, tumors that are PBRM1 deficient, tumors that are BAP1 deficient, and tumors that are deficient for both. In the future we are going to see different treatments for different tumor types.

BRUG 22 Conclusions

In conclusion, the discovery of BAP1 and PBRM1 mutations in clear cell renal cell carcinoma, how they relate to each other, and how they affect outcomes establishes the foundation for the first molecular and functional classification of sporadic ccRCC.

These two genes define for distinct subtypes, which I just went over and you have the Hazard Ratios and p-values written down there. These two tumors are not only associated with different outcomes, but they are also associated with different activations on the mTOR1 pathway and gene expression. Finally we identify mutations in BAP1 which define a novel clear-cell renal cell carcinoma syndrome. I have forty seconds left!BRUG 23 nnRCC graphic

I will go through these very quickly. Suffice it to say, we have also done molecular genetic analysis in non-clear-cell renal cell carcinoma, papillary, chromophobe, oncocytomas, This is now in press in Nature Genetics.

We found that papillary clear-cell carcinoma have more mutations than clear cell carcinoma, whereas chromophobe and oncocytomas have significantly lower mutation burdens, which is depicted there.

BRUG 24 Intr gen analy subtype RCC

These are some genes we found overrepresented– five seconds! You can see the copy number alterations, gene expressions. Anyway, these papers will be coming out next week.

BRUG 25 Associates

Finally, to acknowledge people who did the work in my laboratory, Pena-Llopis. We have had a close collaboration with the people at Mayo Clinic, and also the group at Genentech. We also work very closely with our surgeon and Payal Kapur, our pathologist.

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Pathology and Why It is So Damn Important!

INTRO SLIDE

How Does the Pathology Report Help Direct my Treatment Options?

Lecture by Dr. Daniel Luthringer of Cedars Sinai Medical Center of Los Angeles at Kidney Cancer Association meeting December 2013. https://www.youtube.com/watch?v=-6emPs-mc1E   (Follow via YouTube)

I have transcribed the lecture edited for readability, included the slides, to make it easier to follow.  If you have not seen your own pathology, GET THAT REPORT now. Important to read!

A terrific introduction by Dr. Robert Figlin reminds us of the work of those people we never meet, but who care for us. “One of the people behind the scenes is the pathologist at this and other institutions. Often times the pathologist is in a different part of the hospital evaluating tissue, and helping the clinician figure out what the tissue looks like. It’s become, as Hyung (Dr. Kim) mentioned, time to start to think about personalized approaches to kidney cancer, and the relationship between the pathologist, the surgeon, and the clinician becomes ever more important. Dr. Daniel Luthringer is Professor of Pathology and Section Chief of the Genitourinary Pathology. He will talk to us about how the pathology report and how what he does– is important to then what we decide how to go forward with treatment.”

Dr. Luthringer begins:

“Thank you, Bob, for this introduction and the ability to speak at this conference. I am the guy behind the scenes, at least at this institution responsible for doing the histologic/microscopic analysis of genitourinary malignancies, primarily renal cell carcinomas. (RCC)

1 PATH 1 PathReportTypesThere are really two main categories of specimens we receive, samples from the real tumor itself, which can either be biopsies or resections, as Dr. Kim alluded to, or samples from a metastatic site, a recurrence or a metastatic site. The most common specimens that we see are nephrectomies, resections of the tumor, andeither partial nephrectomy or complete nephrectomy.

2Path 2 Types of Spec These are examples. A partial nephrectomy, as per Dr. Kim, are smaller resections or partial resections of the entire tumor.They include a bit of nephric fat and a little bit of the perinephretic fat as well. The goal is to get the entire tumor out, with a negative margin of resection. With tumors that are bigger generally, or infiltrative, we tend to get the entire kidney. This is an example of a nephrectomy with perinephric fat, the sinus fat, drainage area down here, maybe an adrenal gland up top and this would be an example of tumor that is completely resected.

Occasionally we will get tumors from metastatic sites or—unusually from the primary tumor—and will get a core biopsy, which is really a small smaller sample of the tumor mass. Usually it is about a millimeter or two in diameter; it’s a core, maybe up to several millimeters up to a centimeter in length. Generally, it is just a small sample of a much larger tumor .

Path 3 Speci Handling3  A bit about the specimen handling: within a few minutes of having the tissue removed, it comes to the pathology lab. We do some initial assessment on it.  We have work stations where they will come and the pathology team will assess it. Assume it is a nephrology specimen.  We look at it and measure it, cut it open, procure some of the tissue.  If there is some tissue that needs to be taken fresh, potentially for a biobank to be stored away, or if some tissue needs to be taken for immediate diagnosis or margins or something like that, we will do that.

If you’re enrolled in a study where there some fresh tissue is needed, sent to a particular institution or a reference laboratory for an analysis, we will procure that as well and make arrangements to send it off on an immediate basis. At that point we do photography, tissue fixation and over the next few hours we will dissect the specimen, will analyze it, do a lot important evaluation with our eyes and ears, whatever it takes. Then we will take what are called representative sections of that tumor or specimen, put them. We put them into these little capsules called cassettes and then we process them overnight in these tissue processors. These are pretty standard from institution to institution.

Path 3a Specimen Handling3a The next morning the tissue is taken out of the processors and is manually placed in these other tissue cassettes which are filled with paraffin wax essentially. They are embedded into these wax molds, and then the blocks. Then very thin sections of 4 to 5 microns are cut with these special microtomes and they are picked up on the glass slides. They are again processed, stained, and cover slipped. Ultimately we get a sample of glass slides from that tumor that has been removed.  On an average partial or complete nephrectomy, we will go anywhere from 5-10 paraffin blocks, equating to 5 -10 glass slides.

Path 4 Speci Handling2This takes about a day or two to complete this. Then the initial slides are delivered to the pathologist, who will begin the process of microscopic analysis. He uses obviously his microscope and whatever tools he needs.

He’ll be looking at those sections from the slides, and it will usually be the sections from the kidney, maybe some lymph nodes, margins, adrenal glands, things that were provided by the surgical resection. The whole process usually takes 2-3 days to complete. There is a bit of a time lag, due to the technical processing involved.

Path 4a Import element of report4a The Elements of the Report. Once we generate the report, and it becomes available, there are really three categories of information that are really relevant– not just the diagnosis, but the future care of the patient. The first is the diagnosis. What is the diagnosis? Is it really renal cell carcinoma or is it some other unusual type of renal cell cancer? I will talk more about that. Then: aspects related to cancer stage–tumor size, local infiltration. Has it metastasized or spread? Last, the other features that Dr. Kim alluded to in his talk—resection margins, grade, vascular invasions. We will talk to about these just briefly.

Path 4b Not all masses4bThe first aspect is diagnosis. The important thing to remember, and I think everyone in the room is a little bit beyond this, but remember that at the initial phase, tumors are resected and often times it is not know if it is a RCC. Often times it isn’t even know if it is a neoplasm at all. Not all tumor masses are neoplastic or malignancies.

Path 5 Exp of non cancer tumors 5 Examples of non-tumor masses would be like cysts, a lot of cysts. A lot like this or areas where the collecting system is dilated called hydronephrosis or multiple cysts can present or look just like a RCC. They are resected as if they were RCCs. But in fact they are not—they are benign

There are other types of tumors besides kRCCs. Angiomylipomas are a very common tumor. They could be very big like this one. Here’s a kidney. Here’s a big one. They could be multiple. Here’d two. They could be small one or 2 cm like this, but they all look like fatty tumors, but not all RCCs. Different types of tumor like fibroma or oncocytoma can be very big and aggressive-looking, but in fact, they’re not malignant at all.

Path 6 ex of cancer not RCC6 There are other types of malignancies, true malignancies of the kidney which are not real carcinomas. Urothelial tumors, those that are derived from the lining of the kidney that can extend into the kidney, be derived of the kidney. These are examples of some of these here. They were resected, thinking that these are probably RCCs, but in fact they turned to be urothelial, not RCCs.

Different types of tumors like sarcoma can be derived of the kidney or around the kidney. Other types of tumors can metastasize to the kidney or near the kidney. Adrenal tumors, lymphomas—there is a whole host of malignancies which can mimic RCC.

Path 7 RCC7 What were really talking about today here obviously is renal cell carcinomas which represent probably 90% of more of all true malignancies of the kidney. These are the tumors which are derived from the renal tubular epithelian cells, those little ducts that line the epithelium of the kidney. The diagnosis of RCC really is contingent upon microscopic analysis. You can’t make the diagnosis any other way.

The pathologist needs to look at the gross, take a section, look under the microscopic, and then there’s a spectrum, a range of features that will ensure the diagnosis or put it into a diagnostic category of RCC. Sometimes is not so simple. We need special testing–the use of antibodies, immunohistochemical studies or even as Dr. Young Kim alluded to, sometimes we need to refer to some molecular analysis to put it into a diagnostic category of RCC.

Path 7a RCC Subtypes7a Once we’ve done that, the next phrase is to determine the subtype. There are many different subtypes of RCCs really based primarily on the appearance of the tumor cells and their architectural growth patterns. Sometimes they can rely on immunohistochemical, some of the molecular properties or genetic profiles that put it in the proper subtype category.

Now the subclassification of RCCs and probably this is familiar. You’re familiar with RCCs and it is not so simple. It’s an evolving, sort of complex and ever-changing categorization. In fact, the overall categorization of subtypes just changed a few months ago. We like to think about RCC and subtypes in a sort of developmental pathway.

There is a sporadic type– that which just happened to occur–which is probably the type of cancer that most people in this room happen to have. Those are our typical clear cell, chromophobe, papillary renal cell carcinomas or maybe a few of the other rare variants.

There are those which tend to be familiar; these represent 90+ percent of all RCCs. The familial patterns–again what is associated—they are pretty rare. They are associated with and in families, multiple tumors. Different family members can have these, and we will talk a little bit more about these. There is actually going to be a talk about later in the afternoon or the morning about genetic-based or familial-based RCCs.

There are those rare—really associated with treatment of other types of cancers, and there is unusual category when you have scarred or damaged kidneys. Those kidneys are at risk for developing RCC.

Let’s move through this little bit. Once we have made the diagnosis of RCC, we’ve sub categorized it. I know it seems complex, but there are really only three or four main subtypes that we really need to talk about, especially in the context of a setting like this.

Path 8 RCC Most types8 The most common subtype is the clear cell type. This represents about the vast majority of all sporadic types of renal cell carcinoma. Then there are the papillary and chromophobe renal cell carcinomas. Since these are really the usual types. The much less common type is collecting duct carcinoma which is really more like a urothelial cancer, it behaves like a urothelial cancer, it’s a more aggressive type of RCC.

These are really the main four that we need to be concerned about. They are each unique based on their gross appearance and these are all partial nephrectomies (this is complete down here). Look at their gross appearance. They are very unique under the microscope. Look at their microscopic appearance.

The clear cell is clear, the papillary, very architectural pattern of a papillary tumor. These are chromophobe. This unusual eosinophilic cytoplasm are the tumor cells. Probably doesn’t mean a lot to you, but it means a lot to us, also to some other clinicians. So they have very characteristic gross, microscopic and they are very unique biochemical—and as Dr. Kim alluded to—very specific molecular and genetic profiles as well. This is all really evolving as we speak.

And we all know—this is small graph—that these also behave differently, Some behave better than others, so it is really important that we subclassify these RCCs based on their appearance—all the appearances that we talked about.

Path 9 Potential Therap Implic9 The other thing that Dr. Kim alluded to, and I think we are going to talk about this a little later, and I won’t get into detail on this, but just to point out that the sub-classifications, the sub-categories, they respond differently to the different armamentaria that we have in terms of treatment modalities. So it’s very important for the pathologist to sub classify the type of RCC.

Path 10 typ report10 So on any standard pathology report, you are going to see the diagnosis, RCC, then the subtype, buried somewhere in the report; It will say, clear cell type, papillary type, chromophobe. That’s a very important part of the report.

 

 

 

Path 11 Imp Elements of path11 After diagnosis, the next important aspect is the cancer stage; The cancer stage is really defined by the size of the tumor and its local growth. Is it extending, is it staying confined to the kidney, outside the kidney to the local fat, is it going into any regional lymph nodes that might have been removed during surgery, or was it extending into the adrenal gland, which might have been removed as well? So we analyze each case on what we have and what we see.

This is a typical example of a partial nephrectomy specimen of clear cell carcinoma with a margin that’s out here. Here it measures about 2.1 centimeters the margin is negative. This is a very small tumor of clear cell RCC. This would stage out at T1a, pretty low stage tumor. This would have a pretty good prognosis based on that staging profile.

Path 12 Imp elements of Path 212 Now compare that with this tumor which is a complete nephrectomy specimen, shown the kidney, a lot of nephritic fat. Here’s the sinus of the kidney and here’s the tumor out here. Much bigger, about 9 centimeters and it is growing into the fat. It’s growing into the sinus fat; it is demonstrating more aggressive local growth. This would stage out—this is a microscopic showing it extending into fat. We would stage this out at T3a tumor, as it is obviously larger and more infiltrative.

Path 13 Imp Elements313 A different example would be the same thing. A RCC clear cell type; this is a full nephrectomy specimen. Here’s the kidney. Notice that the tumor is extending into the renal vein. This is another feature that we analyze and look for. We look for it grossly and microscopically and look for tumor extension into that vein, because that will upstage the tumor, overall tumor stage, and this is associated with generally adverse outcome. It is telling us this tumor is behaving more aggressively with local growth. We might see a lymph node, with metastatic clear cell RCC. Again, another aspect we would examine grossly and microscopically.

Path 15 Import elemts 515 So we take all these features, once we have analyzed the tumor and we apply the grading system created by the Joint Council on Cancer Staging, the AJCC and we apply the pathologic stage. Why? Because as Dr. Kim alluded to, we all know, that cancer staging, and it is true for any type of cancer, the higher the stage, the more aggressive that tumor will likely behave therefore the therapy needs to be tailored to their particular stage. And the report should indicate clearly dictate the tumor stage. And that’s part of the standard reporting. Any good cancer report.

Path 14 Impor Elements 414 The final cancer features I’m going to talk about we’re talking about are; resection margin, the grade, vascular invasion, tumor necrosis and this this unusual rhabdoid or sarcomatoid differentiation. These are elements which go beyond cancer staging and the diagnosis. Here’s two examples.

Path 16 impor eleme616 Let us talk about resection margins. These are indirectly related to or they indicate the local aggressiveness of a tumor, if they are growing to a margin. It’s ideal when a partial nephrectomy or a complete nephrectomy is performed, as we have here, the surgeons always try to get the whole thing out so we achieve negative margins . That is optimal. Sometimes it’s not possible, especially if we have a high stage RCC like this one which is extending into fat. Sometimes it’s impossible to get a clear margin. This might get portend some additional therapy when it comes to therapeutic– time for a therapy . With a smaller resection sometimes it’s impossible to get a negative margin or the surgeon needs to go back and take cleaner margins. That interpreted for frozen section analysis, and clear out that margin, again because optimally, we want to achieve a negative resection margin.

Path 17 Imp elements 717 The next factor is vascular invasion. When the tumor invades into those lymphatics that Dr. Kim talked about in surgery. They have a propensity for them to go to the lymph node or they can go into veins or even sometimes arteries and then they have unfortunately, the capacity to go to the lungs or bones or other sites. Those confer an adverse prognostic indicator. Those are an indicator that this tumor might behave in a more aggressive manner. So if we see it microscopically, we include it in the report. Also if there’s tumor cell degeneration and necrosis, that is usually associated aggressive growth in the tumor and we will report that, too. Sometimes that will dictate how the next round of therapy will be undertaken.

Path 18 Imp elem 818 Dr. Kim already talked about tumor grade. We apply–the pathologist applies the tumor grade. The Fuhrman grade is the one that is used for RCC, and it a grading system for 1 to 4. Really, it delineates the degree of differentiation. Grade 1s are well-differentiated tumor, grade 4 are poorly differentiated and in any type of tumor–doesn’t matter if it’s breast, color, renal cell carcinoma–generally well-differentiated tumors behave better than poorly-differentiated tumors.And we assign a grade based on our observations.

Path 19 Imp Ele of report19  Finally, sarcomatoid or rhabdoid differentiation. Most tumors will have just one type of differentiation. This is an example of RCC. The vast majority are RCCclear cell, the conventional type. But in it, there were some pockets where the tumor cells had this unusual morphology under the microscope, called sarcomatoid differentiation, or over here, with we had this rhabdoid differentiation. You can see it that it’s very different than clear cell. These, for whatever reason, are associated with tumor aggressiveness. So when we see this, we need to report it. We need to quantitate it, and we put it in the report because these mandate some additional therapy, independent of stage, because they are really associated with aggressive tumors

All these last category features that I talked about, once we have observed them, we include them in the report. Again, usually any standard RCC report will have these features included in them because they will really impact upon therapy. *See slide10

Path 20 Hereditary20 Two quick categories and I will be done here.I was say a couple of words about hereditary genetic syndromes associated with RCC. This is taken out there that long list that I presented a few slides back. We all know that there are well-known, well-defined syndromes–genetic syndromes or familial syndromes that put you at increased risk from dying from other neoplasms, including RCC, notably Von Hippel Lindau, tuberous sclerosis, Birt-Hogg Dube, these sorts of things. The bottom line: as a pathologist, I can’t look at most of these tumors and say, “this is a clear cell carcinoma. It’s clearly Von Hippel-Lindau, tubersclerosis, or whatever.” All I can say is that it is clear cell carcinoma.

Path 21 Hereditary Genetic21 There are a few types of tumors that I can look at and say, if they have unusual morphology, like this tumor up here, or this tumor up here (references images) , they don’t comfortably fit into the typical types of RCC. Maybe it is a syndromic-type of carcinoma. Very, very rare, less than one percent that we would ever suggest to a clinician that maybe this is syndromic. What we can do is when we get samples like a renal resection like these three different cases, where there are multiple tumors. Here we have multiple tumors or multiple cysts—here we have maybe 20 or 30 different tumors in the particular kidney—or here’s a younger patient with one, two, three separate tumors. Then we can suggest that there is something odd about this, as we usually don’t see this in sporadic type tumors. Maybe it is associated with a genetic syndrome. So; multiple tumors, cysts, a young age, presentation of a renal cell carcinoma of unusual histology, we will suggest to your treatment team that maybe this is a genetic or syndromic pattern of RCC. There’s going to be more on this topic later this morning.

Path 22 Secondary Reviews22 The final topic I was asked to talk about the performance of secondary slide reviews. It’s kind of important. It’s really important when you come to an institution for definitive therapy, it’s always good to have that team—and we do this all the time—review the outside slides to be sure that you have an expert team who works with your treating physicians. We work as a team through tumor board reviews and discussions, and almost every discussions–.                                                                                                                                                       Almost every single individual case, to ensure that we have the correct diagnosis. We have the critical elements included in that report. The specific special testings have been performed, and we have accurate diagnosis and staging and things like that. What you need to do is provide, when you come here, is a copy of the reports, a set of the glass slides, sometimes we call them the recuts. That is all we need to provide an incoming secondary review.

The other scenario when you go off, you might need to off somewhere else for some additional testing for some additional therapy. In that situation, you might need to take, or you should take a set of slides with you to that institution because they will probably want to the same thing and review to ensure that we are all talking about the same disease process.

Remember that your slides or blocks, when you are treated here, or whatever institution, generally those tissue blocks are stored in an incredible huge file, either in the basement of the hospital right below us here or in a warehouse as we have done down in Torrance. T. They are basically saved forever. So when you need to go somewhere in five or ten or fifteen or twenty years, God forbid that there is a recurrence, and you need to get some additional testing, we can pull those blocks out from Torrance (CA) and create a second set of recuts, or a third or fourth set. We can send it off wherever it needs to go for some additional testing or evaluation.

Path 23 Authorizat23 What you need to do is fill out this authorization form here at Cedars if you are being treated here at Cedars. All you need to do is check off “Get a copy of the pathology report” and please provide a set or recut. It’ll take a few days, three days. We’ll get that for you, send it where it needs to go, or we can give it to you directly and you can just carry it with you to that next institution or wherever you need to go.”

With that Dr. Luthringer thanks the KCA, the audience and Dr. Figlin for the chance to speak.  And with that, I agree remind you to get a copy of your own pathology report, and know where your slides are stored. If there is any questions as to your own pathology, if the tumor seems to be unusual, or of an especially high grade, do yourself and your family a big favor, and discuss whether a review of your slides is in order!

With this rare disease, and the complexity of doing the kind of analysis you see here, do not be afraid to get that second opinion.  Go back and see so that pathology may affect the treatment options given–very important!

 

 

 

 

 

 

 

 

 

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Genetic Sequencing for Dummies and Me–not necessarily in that order.

The following is the transcription of the above YouTube video, explaining how DNA sequencing of tumor cells can guide treatment. Thanks to the University of North Carolina for posting this. A terrific explanation. (And it’s OK to view it a few times!)

“You were composed of cells–lots and lots of cells. Each of your cells contains DNA which is its instruction manual. If you are exposed to lots of things that cause cancer, so are your cells. If you lay in the sun, your skin cells get burned. If you smoke cigarettes, your lung cells get their nicotine fix. Exposure of cells to carcinogens can damage their DNA. Sometimes when cells divide, DNA can be damaged–just by bad luck.

Damage to DNA is usually repaired, but sometimes it is not. When damaged DNA goes unrepaired, the cells receive bad instructions, and can turn fromhealthy cell to cancer cells. Cancer cells divide too fast and crowd out other cells and grow with they are not supposed to grow. When cancer cells cling together, they form a tumor that might be found by a doctor or a patient.

Today most patients are treated based on what a piece of tumor looks like when viewed under the microscope. This is how oncologists have done it for 50 years. While this approach is better than nothing, it doesn’t work that well. Even if doctors agree what type of cancer a patient has, it does not always mean it is clear what is the best therapy to treat that patient’s cancer.

Recently, it has become clear that the cells instruction manual the DNA determines how s the cancer will to behave and in particular, it determines if it will grow quickly or slowly, if it will respond to one kind of therapy or another, and if it will be cured or come back.

Given that the cancer’s DNA is so important in determining how it will behave, doctors and scientists at the UNC Lineberger Comprehensive Cancer Center have determined to treat patients based on their and their tumor’s DNA. This approach relies upon new DNA sequencing technology, called massively parallel sequencing or next generation sequencing. So we call the Lineberger effort “UNseq”.

Here’s how it works. When a patient with cancer comes to UNC and agrees to participate in our study. Some normal DNA is taken from the patient, usually their blood and some DNA is collected from the tumor. From the tumor DNA and normal DNA are broken into smaller pieces and the importance pieces of the DNA are captured. This capturing is important so we don’t have to sequence all the DNA of a patient, just the DNA which is important in cancer. It is like going into a gigantic library and choosing the one book on cancer ignoring all the other books on eye color or heart size or height.

The captured DNA from the tumor and the normal tissue are then processed using next generation sequencing. After sequencing, we have two gigantic books of DNA sequence. One is the tumor’s DNA and the other is the patient’s normal DNA. Although the captured DNA is much smaller than the patient’s entire genetic sequence, each book is still several million letters long.

The tumor DNA book and the normal DNA book are then compared letter by letter. In most places the books are the same, but in a few places the letters are different. These differences represent mutations in the DNA, that resulted from DNA damage. Finding all the mutations involves a lot of math, but eventually, UNseq identifies all the mutations that are present in the cancer cell and not in the normal DNA .

Just having a list of the mutations is not the end, however. Only a small number of the mutations change what the cancer cells do. Most mutations are harmless. Whether a mutation is good or bad, largely depends on what gene it affects and what part of the gene it affects.

Once the list of mutations has been identified, a team of doctors sits down together and review the mutations at the molecular pathology tumor board or the MTB. Each mutation is reviewed. Some mutations are clearly innocent. Some mutations are clearly bad. For some mutations, it is unclear of their importance and the MPB not always certain what to do with these.

This is all done by doctors were not directly involved in the patient’s care, s so that similar decisions are made about the same cancer.

Once the bad mutations are found, they are confirmed by another clinically approved test. Information about the mutations that are confirmed is given to the patient and their treating doctors.

With this knowledge, the patient’s care can be more tailored or focused. The doctor may decide the patient to try a different therapy. The doctor may decide that the patient has a better or worse chance of recovery. Sometimes the DNA looks makes the cancer look like a different cancer than was found under the microscope. New treatment plans based on DNA sequencing are called targeted therapy.

Importantly, UNseq does not put patients at risk. If there is a good therapy for their cancer, they get that therapy. UNseq only changes care for patients who do not have any good options left. Unfortunately, that is a common problem for cancer patients.

Some day soon, we believe all cancer treatment will be targeted, that is based on what the tumor DNA, rather than what the tumor looks like under the microscope.

Doctors at UNC recognize that technology moves at a rapid pace, but applying new technology to patients can be slow for patients with advanced cancer. Having successfully implemented UNseq, UNC physicians are building upon the approach to develop a range of advanced tests for patient care. We believe that these new approaches will help patients with cancer live longer and better lives.”

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Adaptive Immunity in Cancer Immunology & Therapeutics–My Summary

I was dying ten years ago. My kidney cancer had moved into my lungs, threatening to choke me to death.The tumor and kidney were gone, but 100s of tiny lung metastases were growing. Lucky to get an FDA-approved immune therapy, high dose interleukin 2, my own immune system was revved up so as to destroy the cancer. Thus, I am intrigued by all things about the immune system and cancer research. “Adaptive immunity in cancer immunology and therapeutics”is one of the most comprehensive explanation of the tumor cell/immune system interactions–that I can somewhat(!) understand.

http://ecancer.org/journal/8/full/441-adaptive-immunity-in-cancer-immunology-and-therapeutics.php

My summary is below, a more patient-friendly version. Don’t hesitate to take on the original, via the link! It is just the kind of article to take to your doctor to discuss immune response meds/treatments. It begins with the “abstract”, a summary of the information to follow.

Abstract: The vast genetic alterations characteristic of tumours produce a number of tumour antigens that enable the immune system to differentiate tumour cells from normal cells. Counter to this, tumour cells have developed mechanisms by which to evade host immunity in their constant quest for growth and survival. Tumour-associated antigens (TAAs) are one of the fundamental triggers of the immune response. They are important because they activate, via major histocompatibility complex (MHC), the T cell response, an important line of defense against tumourigenesis. However, the persistence of tumours despite host immunity implies that tumour cells develop immune avoidance. An example of this is the up-regulation of inhibitory immune monoclonal antibodies in clinical practice have been developed to target tumour-specific antigens. More recently there has been research in the down-regulation of immune checkpoint proteins as a way of increasing anti-tumour immunity.”

Immune Responses in Tumors—A Quick Summary by Peg

Since cancer cells are genetically different from normal cells, they also produce different substances—antigens—which can make them more noticeable to the immune system. Any antigen will generate a response from the immune system—think how the body reacts to an infection, an insect sting or a splinter.
Antigens trigger the immune system into action, keeping abnormal cells from taking over the system—most of the time. To grow, tumor cells develop inhibitory responses to limit or down-regulate those immune responses. An over-active immune response can be problem, well-known to those with severe allergies or auto-immune diseases like lupus. Keeping the proper balance is the norm for the immune system, despite ongoing external and internal changes

Using knowledge of these interactions to support the immune system, researchers have develop agent/medications. These are intended to strengthen the beneficial responses, and to prevent the tumors from suppressing or down-regulating those desired responses. Some monoclonal antibodies can effectively target these tumor-specific antigens and trigger tumor death or inhibit such growth. Some of these new agents include bevacizumab (Avastin), rituximab (Rituxin), alemtuzumab (Campath or Lemtrada), bortezomib (Velcade), denosumab (Xgeva) and trastuzumab (Herceptin), among many others, and for a variety of cancers.

Be aware that these agents may be called by the brand name, as Sutent, or the scientific name, as sunitinib, and may have several brand names for different cancers. Just another new challenge to all of us newbies.

Tumors exist with a system of structures, various types of cells and with a chemical signaling process. These shifts away from the normal cells and organs produce tumor antigens. The immune system notices the antigens and works to destroy the foreign cells. Then the tumors shift to counter the immune response in an endless signaling battle. It is a dynamic “fail-safe” system, with multiple checks and balances, work-around pathways, evasive signaling, and constant testing to maintain itself. When this system does fail, a tumor can be established and move to different sites.

Solid tumors have a tumor core, a margin that is invading into a healthy structure–blood vessels or layers of an organ–and lymphoid components. This can vary patient to patient, despite the seeming similarity of tumors, and vary from one metastatic tumor site to another. Inside the tumor will be the immune-cell types–macrophages, dendritic cells, natural killer (NK) cells, mast cells, B cell, and T cells. Different immune cells can be found in different parts of the tumor, and the variation and the density of these cells may play a role in clinical response. It may be that this reflects the robust nature of the natural response to the tumor invasion, or reflect that the system is being overwhelmed by the tumor. Others think that the infiltration of immune cells can be utilized the support of the treatments given to the patient.
The linked journal article goes into detail as to the various types of responses, including adaptive immunity, immune editing and immune evasion. In summary, there are numerous approaches to limit tumor growth within the complex system of antigens and immune responses.
As immune cells infiltrate a tumor, that infiltration can be measured. What is the meaning of a higher or lower level of immune cell infiltration? The following paragraph sums up the challenge of using tumor infiltration as a marker of prognosis or treatment response.
It is a commonly held belief that infiltration of immune cells into tumor tissues and direct physical contact between tumor cells and infiltrated immune cells is associated with physical destruction of the tumor cells. That can reduce the tumor burden, and improve prognosis. An increasing number of studies, however, have suggested that aberrant infiltration of immune cells into tumor or normal tissues may promote tumor progression, invasion, and metastasis. Neither the primary reason for these contradictory observations, nor the mechanism for the reported diverse impact of tumor-infiltrating immune cells has been elucidated, making it difficult to judge the clinical implications of infiltration of immune cells within tumor tissues. J Cancer 2013; 4(1):84-95. doi:10.7150/jca.5482

Tumor Infiltrating Immune Cells—a Good Sign or Not?

If the immune system is at work, immune cells infiltrate the tumor to work directly against the tumor cells, is the tumor destroyed? Does the body naturally destroy the tumor? Does the patient benefit from medical treatments which support the immune system? Unfortunately, the presence of the tumor-infiltrating cells can mean very different things, with a better prognosis in one type of cancer, and a poorer prognosis in another.

Monoclonal antibodies can target antigens in blood cancers and solid tumors. In blood cancers, antibodies counter several cluster of differentiation (CD) markers, and in solid tumors, growth factors such as EGFR (epidermal growth factor receptor) or angiogenesis factors, such as vascular endothelial growth factor (VEGF). The mechanisms of action can lead to direct cell death, or simply impede its growth or inhibit checks on the immune response.

Normal cells are naturally programmed to die, but cancer cells do not “follow the program”. When certain proteins on the surface of cells bind with one another, the expected immune response is inhibited. These anti-PD-1 (anti-Programmed Death-1) proteins bind with other proteins, the binders or ligands, PD-L1 and PD-L2. Studies indicated these agents can help the immune system, with some disease stabilization or tumor shrinkage. Recent trials show some response by 20-25% of patients, some of whom had failed previous treatments. Some responses lasted more than a year. In a few cases, some responses were lasted for a period after stopping the medications. Newer trials will likely combine several of these therapies. This is not without risk, as some had severe side effects, and several patients  died from such side effects.

Nevertheless, the earlier successes with this approach and the increased knowledge of the various immune responses to be targeted will continue, especially in combination studies. This work will have impact on existing immune therapies, as does the more integrated approach to cancer treatment.

I welcome any comments and corrections, and remind you that I am a patient, and am not a medical professional. My goal is to help educate other patients to receive the best understanding of their illness and best possible treatment.

Peggy Zuckerman

peggyzuckerman@gmail.com

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Gene Sequencing? What is it? Does it Matter? (* *YES***)

We hear about gene sequencing and personalized medicine, and yet few of us really understand what that means. All of this, despite the hype! We also hear about targeted therapy. As a minimum that should mean that doctors are targeting the tumor for destruction, but is not that easy.  As usual.

The University of North Carolina researchers have done critical reviews of clear cell kidney cancer. They questioned why there is such wide variation in the aggressiveness of clear cell RCC (ccRCC). Almost all ccRCC looks alike under the microscope, the usual “pathology” report, but tumors don’t behave the same. Some are shockingly aggressive in their growth, even the small ones.  They metastasize quickly, and break the surgeon’s “got it all” prediction.  The overall survival (OS–the longer, the better!) is wildly different, despite the similarity.

If this is the same kind of cancer, why does it behave so differently?

The obvious answer is that these tumors are not really the same biologically. That can be shown by an inside look at the tumor’s DNA and patient’s normal kidney DNA. This is what gene sequencing can do, i.e., help define what differences exist in the tumor cell. This is essential in “targeting” the treatment to the tumor. You have to see the recognize what IS the target to hit it with the right treatment.

This linked YouTube lecture below helps explain these new terms. It gives me appreciation for the challenge faced by researchers, clinicians and patients in getting proper treatment.  And nobody cares as much as we patients!

Dr. Kimryn Rathmell and colleagues at U of NC created a test which can differentiate the more aggressive form of clear cell kidney cancer from a less aggressive form.  Should one monitor a smallish tumor, monitor a patient more closely after surgery, or just assume everything is fine and dandy?  These tests help in that decision.  (PS Don’t forget that a “small” Stage 1 kidney cancer tumor can be the size of a golf ball.  “Regular” size Stage 1 tumor can be the size of a nice tomato.  Small, indeed.)

We’ve learned it isn’t just “cancer”. It’s not just “kidney cancer”. It’s not even just just “clear cell” or “papillary” or “chromophobe”! Instead it is a molecularly defined cancer which has taken up residence in one’s kidney. Different drivers, some more aggressive than others–big surprise.  Different strokes for different folks, and different targets for different testy genes in our tumors!

https://www.youtube.com/watch?v=Y9HumO20GKc A transcription can be found in “Genetic Sequencing for Dummies and Me”

 

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