Coincidentally, when I experienced my PSA recurrence of prostate cancer my rheumatologist suggested that I have an MRI to check up on the status of spinal involvement from my arthritis. After going through the usual struggles with the insurance company, I did have the MRI.

While still dealing with the emotional issues of learning about the recurrence, I received a telephone call from the rheumatologist letting me know that my spine was in excellent shape, but surprisingly I had an 18 cm tumor in my left kidney! He urged me to see my oncologist, which I did.

Dr. Petrylak (my oncologist) said that it is very unusual for prostate cancer to metastasize to the kidney, but you never really know. He referred me and I immediately saw a kidney surgeon who arranged for the surgical removal of my kidney.

The pathology lab sliced and diced the tumor looking for any signs of PSA, but they could not find any. The cells looked similar to clear cell renal cancer and since there was no evidence of PSA in the tumor, we assumed that I had primary renal (kidney) cancer. This cancer, as is my thyroid cancer, is unrelated to the prostate cancer or its recurrence!

In my Malecare, weekly support group there was a new member in attendance one Wednesday. He too had a prostate cancer recurrence a few years ago, but it had been controlled by radiation to the pelvic region. He too now presented with a tumor of an unknown origin located outside of, but next to his kidney. The various oncologists he saw could not determine the nature or origin of his tumor. He did start hormone therapy (ADT) which did shrink the tumor, so the presumption of his doctors is that this tumor; although in a very unusual location for prostate cancer is probably a prostate cancer metastasis.

Treatment decisions and other cancer management issues should be clearer, however, historically we have not had the tools to differentiate and describe certain tumors. The traditional tools used to identify uncertain tumors include imaging studies such as CT scans and MRIs, but they are not effective. This situation may now be changing.

The FDA recently approved the Pathwork Tissue of Origin Test for Hard to Identify Tumors. This test analyzes a tumor’s gene expression pattern to help a pathologist identify a tumor. The Tissue of Origin Test matches the genetic fingerprint of the questionable tumor against 15 common, prostate cancer included, cancers. The test uses a microarray to measure the expression patterns of more than 1,500 different genes to identify the tumor. The test has proven to have a success rate of 94%.

It is estimated that up to 200,000 cancer survivors annually develop tumors that are of an uncertain nature and so their treatment options are not clear. Knowing the origin of a tumor; is it a new cancer or a metastasis will help to insure that proper treatment protocols are used. Without this type of test, the treatments are at best educated guesses.

Download the Pathwork Tissue of Origin Test information sheet.

Joel T Nowak MA, MSW