Prostate‐specific antigen recurrence and mortality after conventional dose radiation therapy in select men with low‐risk prostate cancer

Abstract

Prostate-specific antigen (PSA) recurrence, prostate cancer-specific mortality (PCSM), and all-cause mortality (ACM) were evaluated for men age >70 years receiving conventional dose external beam radiation therapy (RT). Between January 1, 1989, and December 1, 2002, 358 men were treated with RT for localized prostate cancer at a Harvard Medical School Affiliate in Fall River, MA. Median age was 71.2 (range, 43.2-83.5) years and patients were followed for a median of 4.0 (range, 0.2-13.5) years. Univariable analysis demonstrated that increasing pretreatment PSA velocity was significantly associated with increasing pretreatment PSA (P < .0001), Gleason score (P = .0002), and shorter post-RT PSA doubling time (P = .0007) but not with clinical T-category (P = .09) or percent positive biopsies (P = .08). For the select cohort of men age >70 years with low-risk disease and a pretreatment PSA velocity < or =1.0 ng/mL per year, all deaths observed to date have been from nonprostate cancer etiologies. Whereas PSA recurrence in this group reached 43.3% by 7 years, due to the advanced age of the cohort and less aggressive biology, competing causes of mortality predominated as the cause of death despite PSA failure. In men age >70 years with low-risk prostate cancer and pretreatment PSA velocity < or =1.0 ng/mL/year, prostate cancer death was not observed despite a modest PSA recurrence rate.