Two independent research groups have identified separate gene expression profiles in peripheral blood that can predict survival in patients with castration-resistant prostate cancer (CRPC). One team, led by researchers at the Institute of Cancer Research (ICR, U.K.) identified a nine-gene expression signature in the peripheral blood of prostate cancer patients that identified those with aggressive castration-resistant disease, and could further distinguish between those CRPC patients with low overall survival (averaging 9.2 months) after treatment, and longer survival that averaged at nearly two years.
A second set of published studies, reported by researchers at Mount Sinai School of Medicine’s Tisch Cancer Institute, identified a six-gene expression profile in the peripheral blood of CRPC patients that separated patients into two risk groups: a low-risk group with median survival of over 34.9 months, and a high-risk group with a median survival of just 7.8 months. Interestingly, the differential expression profiles identified in both studies indicated that dysregulation of the immune system may play a role in the aggressiveness of CRPC.
Additional studies are already under way to further validate the six-gene signature in CRPC patients, and evaluate whether it remains stable during the whole course of a patient’s illness, and the predictive ability of the signature in patients with prostate cancer who are treated using immune-based therapies.
“Blood from patients with prostate cancer contains mRNA expression information that is prognostic in patients with castration-resistant prostate cancer,” concludes Johann de Bono, M.D., who heads the prostate cancer targeted therapy team at the ICR. “Expression array analyses of blood merits further assessment in predictive and pharmacodynamic biomarker studies for new anticancer drugs including immune therapies.”
Professor de Bono et al describe their findings in a paper titled “Prognostic value of blood mRNA expression signatures in castration-resistant prostate cancer: a prospective, two-stage study.” The Tisch Cancer Institute team’s work, headed by William K. Oh, M.D., is reported in a paper titled “A whole-blood RNA transcript-based prognostic model in men with castration-resistant prostate cancer: a prospective study.”