[2006] [663] Prostate-Specific Antigen Failure and All Cause Mortality

Anthony V D'Amico*, Marian Loffredo, Andrew A Renshaw, Boston, MA; Ming-Hui Chen, Storrs, CT.

Introduction and Objective: While prostate-specific antigen (PSA) failure following primary therapy triggers secondary therapy in most men, who, how and when to treat following PSA failure in order to avoid dying from prostate cancer remains unknown. In this study, we evaluated the impact of prostate-specific antigen (PSA) failure on mortality. Methods: The study cohort comprised 206 men enrolled on a prospective randomized trial evaluating external beam radiation therapy (RT) with or without androgen suppression therapy (AST) for a PSA > 10 ng/ml and/or a Gleason score 7 or greater clinically localized prostate cancer. The median age at PSA failure was 74.8 years. Salvage AST was administered at a PSA of 10 ng/ml. The post-therapy PSA doubling time (DT) by category (< 6, 6 to 12 compared to > 12 months), age at the time of PSA failure (continuous) and treatment were assessed using a Cox regression multivariable analysis for their association with mortality following PSA failure. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated. Results: After a median follow up of 7.3 years in living patients, treatment (p = 0.67) and a PSA DT of 6 to 12 months (p = 0.71) were not significantly associated with length of survival following PSA failure; whereas a PSA DT < 6 months (HR: 4.9: [95% CI: 1.1, 23]; p = 0.04) and age at the time of PSA failure (HR: 1.1 [95% CI: 1.03, 1.26]; p = 0.009) were. Death due to prostate cancer was not observed in men with a PSA DT > 12 months; whereas by 5 years following PSA failure 5% as compared to 63% of men were estimated to die of prostate cancer if their PSA DT was 6 to 12 as compared to < 6 months respectively. Conclusions: PSA failure did not lead to a significant shortening of overall survival unless the PSA DT was < 6 months. Men who are otherwise healthy and experience this type of PSA failure should be enrolled on to randomized studies examining whether the earlier use of chemotherapy in addition to AST can prolong survival. Men with a PSA DT > 12 months who are in their mid 70’s at the time of PSA failure may not require salvage AST.

Discussed Poster: Prostate Cancer: Localized (I) (9:00 AM-12:00 PM)