Clinical Trials for Advanced Kidney Cancer : Promise and Peril
Clinical Trials, Promise and Peril
Treatment for advanced kidney cancer is not nearly good enough. In addition, the drug therapies used to treat other cancers such as hormonal therapy and cytotoxic chemotherapy are ineffective in kidney cancer. At the same time, kidney cancer is at the forefront of two of the newest areas of cancer medicine:
- Immunotherapy: Kidney cancer seems to be more sensitive to immunotherapy than other cancers and immunotherapy is both a mainstay of standard treatment, and an area of promising research.
- Anti-Angiogenic Therapy: Kidney cancer, in particular clear cell kidney cancer, is an unusually vascular tumor and may be a particularly good target for anti-angiogenic therapy, treatment which targets tumor blood vessels. It turns out that the extreme vascularity of clear cell RCC is due to a mutation in a gene called VHL, which causes the cancer cells to secrete unusual amounts of Vascular Endothelial Growth Factor (VEGF). VEGF in turn stimulates the growth of blood vessels.
Because these are areas in which knowledge is expanding rapidly, you should certainly consider the possibility of participating in an experimental test of a new treatment, called a clinical trial.
That’s what I did back in 1989, and it saved my life. A clinical trial might save your life too. On the other hand, back in ’89 there was no useful treatment for metastatic kidney cancer. The treatment I got in a clinical trial, IL-2, is now FDA approved for advanced kidney cancer. Yet many patients with metastatic renal cell cancer who go to major cancer centers are offered early phase clinical trials of treatments which have no real track record in renal cell cancer as initial treatment. In my opinion, patients with metastatic disease should, if possible, get an IL-2 based regimen which has given useful results as first line therapy. Despite its disadvantages, I believe IL-2 therapy is more promising than something for which there are not yet any positive results. Almost by definition.
This certainly does not mean that clinical trials should not be considered. There may well be trials available which add something to IL-2 in the hopes of making it better, or there may be trials testing new IL-2 based treatments which have already given promising results that are being done in order to confirm those results. These would both be worth considering.
If IL-2 doesn’t work, then entering a clinical trial of something really new seems very appropriate. I would, in general, avoid trials of cytotoxic drugs alone because kidney cancer has proven incredibly resistant to this type of therapy in the past, and I would search hard to try to find the most promising trials, basing this mostly on prior results in kidney cancer (Some prior results may be available even with experimental treatments.)
Clinical trials are run under a complex system with special rules. In order to choose a good trial you need to understand how the system works so you can make it work for you. For in depth information, see my Strategic Guide to the Clinical Trial System
There are some superb resources on the net that make it easy to find clinical trials for kidney cancer:
- Of specific interest, the Renal Cell Cancer Evaluated Trials Database is a small database of trials specifically for kidney cancer which is unique because the trials are actually researched and reviewed. (Disclosure: this is another one of my projects!).
- For a broader search, CancerGuide’s list of Internet Clinical Trial Databases should set you on the right track.
Clinical Trials and Surgery for Residual Disease
If you have a partial response to immunotherapy (roughly at least 50% tumor shrinkage with some still remaining), there is what I consider to be good evidence that surgically removing all residual disease can be of great benefit when it is possible. For details, see my article on Combining Surgery with Immunotherapy.
There is ample data showing resection of metastatic disease by itself can be of major benefit if all disease can be removed (See our articles on Surgery for Metastatic Disease for details). Furthermore, the general experience in oncology (and the specific experience with immunotherapy for RCC) is that unfortunately most patients with a partial response will eventually suffer tumor growth. And not only that, partial responses are almost always far more frequent than complete responses.
Given all of this, it seems more than reasonable to presume that after achieving the maximum response to any kind of therapy it would be wise to proceed with surgery as long as all remaining disease can be removed and the surgery is reasonable. Unfortunately, it has come to my attention that patients in some trials are not offered surgery after a partial response unless they are removed from study due to tumor growth. This may be because the investigators don’t believe surgery is of value, or it may be that they want to observe partial responses until relapse so that they can determine the length of those responses. The latter would be an excellent example of a conflict between patient care and research, and one in which you can intervene.
Surgery might still be possible and might still be effective even if you wait for tumor growth before having surgery. But it is also possible that new or larger tumors will make surgery infeasible. It is also possible that even if surgery is done, the more aggressive nature of the now growing tumors increase the chance that it has seeded new tumors. I have no data to estimate these risks, but given the evidence for surgery after partial response and surgery for RCC metastasis in general, I know of no good reason to take risks of this nature at all.
I believe that if you have been treated to maximum response in a trial (or out) and now have resectable disease you should strongly consider getting the surgery even if you encounter resistance from your trial doctor. This emphatically is not a reason to avoid trials. This is a strategy to obtain the maximum benefit when participating in a trial. Treating to maximum response doesn’t mean rushing to surgery the instant there is a sign of response. It means either that you’ve gotten as much treatment as the trial allows, or that the last scans showed no change.
This CancerGuide Page By Steve Dunn. © Steve Dunn
Page Created: January 23, 2003, Last Updated: March 30, 2004