In this multi-institutional post hoc analysis, men with non-metastatic castrate-resistant disease, a PSA doubling time <10 months, PSA>2 continued androgen deprivation therapy and were randomized 2:1 to enzalutamide versus placebo. The goal of this analysis was to assess if previous definitive prostate treatment was associated with differences in survival or metastases in those treated with enzalutamide compared to placebo. In all patients, enzalutamide decreased the risk of metastasis or death by 71%. 28% of patients had previous definitive treatment (cryotherapy and prostatectomy). No differences were demonstrated in the risks of metastasis or death in those who received previous prostate treatment compared to those patients who did not.
In summary, enzalutamide treatment resulted in a statistically significant reduction risk of metastasis or death in patients who did and did not previously receive definitive treatment to the prostate.
This thought-provoking post hoc analysis of PROSPER has interesting implications in prostate cancer biology. Continued investigations into prostate cancer genomics and tumor mutational load may uncover the etiology of these findings.
Presented by: Paul R. Sieber, MD, FACS, Lancaster Urology, Lancaster, Pennsylvania
Written by: David B. Cahn, DO, MBS, Fox Chase Cancer Center, Philadelphia, Pennsylvania, @dbcahn, at the 19th Annual Meeting of the Society of Urologic Oncology (SUO), November 28-30, 2018 – Phoenix, Arizona