Survival in men older than 75 years with low- and intermediate-grade prostate cancer managed with watchful waiting with active surveillance

Abstract

Objective Recent studies have reported the underuse of active surveillance or watchful waiting for low-risk prostate cancer in the United States. This study examined prostate cancer–specific and all-cause death in elderly patients older than 75 years with low-risk tumors managed with active treatment versus watchful waiting with active surveillance (WWAS). Methods We performed survival analysis in a cohort of 18,599 men with low-risk tumors (early and localized tumors) who were 75 years or older at the time of prostate cancer diagnosis in the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database (from 1992 to 1998) and who were followed up through December 2003. WWAS was defined as having annual screening for prostate-specific antigen and/or digital rectal examination during the follow-up period. The risks of prostate cancer–specific and all-cause death were compared by Cox regression models. The propensity score matching technique was used to address potential selection bias. Results In patients with well-differentiated (Gleason score 2–4) and localized disease, those managed with WWAS without delayed treatment had higher risk of all-cause death (hazard ratio 1.20, 95% confidence interval 1.13–1.28) but a substantially lower risk of prostate cancer–specific death (hazard ratio 0.62, confidence interval 0.51–0.75) than patients undergoing active treatment. Patients managed with WWAS with delayed treatment had comparable mortality outcomes. Sensitivity analyses based on propensity score matching yielded similar results. Conclusion In men older than 75 years with well-differentiated and localized prostate cancer, WWAS without delayed treatment had a lower risk of prostate cancer–specific death and comparable all-cause death as compared with active treatment. Those patients in whom treatment was delayed had comparable mortality outcomes. Our results support WWAS as an initial management option for older men with well-differentiated and localized prostate cancer.