Once you have had primary treatment for prostate cancer you must continue to actively monitor your PSA until you die. There is no cure; at least you should never assume that you have been cured because 1/3 of all men who have treatment will have a recurrence. What treatment you have does not matter, statistically you have a 1 in 3 chance of having a prostate cancer recurrence.

It doesn’t matter what your surgeon tells you or your radiation oncologist tells you, you must always be vigilant. Nobody is excluded from the 1 in 3 number!

This situation drives home the issue that we do not have a good, early biomarker that will allow us to determine who will have a recurrence. Finding this biomarker is a priority for many researchers. Unfortunately we remain distant from defining the biomarker, but there are some recent possibilities entering into the research world.

It was recently described that men who had high levels of the activated Stat5 protein in their prostate cancer after a radical prostatectomy were more likely to have a recurrence or die from the disease compared to men who had little to no presence of the growth protein.

This suggests that this protein, Stat5 when activated signals cancer cells to grow and survive. It is possible that activated Stat5 could be a biomarker to help guide patients and physicians for future treatment, researchers say.

Marja Nevalainen, MD, PhD, of Thomas Jefferson University’s Kimmel Cancer Center, Philadelphia, and colleagues examined prostate cancer biopsies and tumor tissues obtained from 562 men who underwent a radical prostatectomy, comparing Stat5 levels with their outcome.

As a control they looked at prostate tumor tissue in 106 men who were under an active surveillance treatment plan and had no neoadjuvant therapy. Samples were taken at the time of diagnosis.

“In both cohorts, if the patient had increased Stat5 in their prostate cancer, that patient was more likely to experience prostate recurrence or die from his disease compared to patients who had very low levels of Stat5,” Dr. Nevalainen said.

More specifically, patients without detectable nuclear Stat5a/b expression had recurrence-free survival of 72% at 8 years. In contrast, patients with high nuclear Stat5a/b scores had a recurrence-free survival rate of 42% at 8 years. This indicates an approximately 30% benefit in recurrence-free survival at 8 years associated with negative status for nuclear Stat5a/b expression in prostate cancer.

For those on active surveillance, patients with low nuclear Stat5a/b scores had a lower probability of prostate cancer-specific death. There was an approximate 50% benefit in prostate cancer-specific survival at 10 years associated with a negative status for Stat5.

The findings support a series of past and ongoing studies investigating Stat5 and its predictive capabilities. She now plans to investigate Stat5’s predictive response after radiation therapy.

“There is an urgent need for reliable biomarkers to identify prostate cancer patients whose cancer is most likely to recur after the initial therapy and progress to advanced disease,” said Dr. Nevalainen. “The data presented here supports the initiation of prospective studies to determine the clinical utility of Stat5 as a prognostic and predictive marker in prostate cancer.”

Findings from the study were published online in Human Pathology (Sept. 28, 2012).

Joel T. Nowak, M.A., M.S.W.