One of the warnings about kidney cancer is that it is sneaky. Researchers call it aggressive and insidious in nature, as there is a 20-40% recurrence rate for clinically localized disease, i.e, small, hasn’t spread, not to worry, etc. There are many patients who feel reassured by the doctor, generally a surgeon, that “we got it all”, and that there was no need for additional follow up. No CT scans, no blood tests, no nothing.
Most patients are pretty grateful until RCC lives up to its sneaky reputation and makes a surprise return. Since the return is indeed sneaky, is it also sporadic? Is there a way to know which of those patients might need far closer monitoring, or should all of these patients have multiple CT scans or just wait until there is a return. Most early tumors are found incidentally, while checking on something else. That “lucky” patient with a RCC diagnosis may be part of the group which will never have another problem again, or part of the 20-40% who gets “lucky” again. That return of disease can also be silent, with the patient at an advanced stage and in far worse shape than the first time around. What to do? CT scans have their disadvantages, and living under a cloud is pretty hard, and getting RCC again beyond discouraging.
Those nameless researchers, for whom I say prayers of thanks often, have a new tool to determine which early RCC tumors are naturally more aggressive. With this info, patients can be monitored more closely, while the others can live with greater confidence. We’ve been hearing about BRCA genes in breast cancer, thanks to the attention-getting Angelina Jolie. Now we are learning about a related protein in RCC. The expression of this protein helps refine the risks of the early stage RCC patient.
Now it gets a bit technical,but it is important to understand the science here to understand its impact. he expression or lack of expression of some genes can impact prognosis, or clinical expectations, in cancer patients. In clear cell RCC, not the rare variants,such as papillary or others, the lowered or negative (or lack of) expression of BAP1 may signal a cancer that is naturally more aggressive than others. BAP1, also called BRCA1 associated protein-1, is an enzyme which plays a role in cell development, can be mutated or changed in breast and lung cancers, which has been recognized for some time. Recently the Mayo Clinic released a report which indicates that the lack of BAP1 in early stage RCC was associated with greater risk of death for those patients. This is important stuff.
How do they know this? The researchers can detect that expression in tumors. They compared its presence with the outcomes of patients described above. They used 1,479 tumors from patients with nephrectomies for localized ccRCC. This is a very large sample, something important in any trial or research of this nature. They were able to test 98% of the samples provided, and found 10.5% were negative for BAP1, 84.8% were BAP1 positive, and the balance were unclear. After 8.3 years of following patients (Notice how long it can take to get GOOD data.), 1,092 patients were alive, and 252 had ccRCC specific death. Those patients who had BAP1-negative tumors were at a threefold increase risk of death compared to those with BAP1-positive tumors.
Thus, the researcher advocate using BAP1 staining, or analyses, post surgery, to monitor those patients at greater risk of recurrence and death from this subset of ccRCC patients who are likely at greater risk.
All the nagging that kidney cancer patients do to one another to be monitored, despite having had small tumor which was supposedly completely excised is not as effective as it should be. Neither is the “Don’t worry, we got it all” attitude that too often impedes a proper monitoring. This new tool is more objective and should be part of the post ccRCC surgery monitoring.
Just to stir up extra trouble, there may be a case for getting a biopsy to use for this testing, when the small, incidentally found tumor is “slated to be ablated”. Would a biopsy be appropriate, in order to see the level of this protein and the aggressiveness of the tumor? Stay tuned.