Survival of men with prostate cancer undergoing radical prostatectomy in Ontario.

Abstract

Radical prostatectomy is traditionally reserved for men with at least 10-year life expectancy. Numerous studies show that survival estimates by physicians are inaccurate. We determined how well men undergoing radical prostatectomy for cancer are prognosticated by comparing observed and expected survival. We performed an observational cohort study using population based data sets to identify each man in Ontario, Canada between 1992 and 2011 who was diagnosed with prostate cancer and underwent radical prostatectomy within 6 months. Observed 10-year survival rates were calculated using the Kaplan-Meier method. Two expected 10-year survival rates were calculated using 1) population life tables and 2) the ADG® score, an accurate, validated index that predicts mortality risk based on patient comorbidities. A total of 36,045 men with a median age of 62 years were included in the study. Median observation time was 8.1 years. Observed 10-year survival was 88.9% (95% CI 88.4-89.3), significantly greater than the expected 10-year survival of 83.3% according to life tables and 76.0% according to ADG score. The observed-to-expected death ratio was 0.66 (range 0.64-0.68) and 0.46 (range 0.45-0.48) using life tables and the ADG score, respectively. Ontario men who undergo radical prostatectomy for cancer have 10-year survival that significantly exceeds that of the population and individuals with similar comorbidities. This indicates that physicians and patients involved in deciding who should undergo radical prostatectomy have done an excellent job at identifying patients with prostate cancer with high survival. We are uncertain how these results apply to patients and physicians outside Ontario.