Survival and prognostic factors of patients with clinically localized prostate cancer

Abstract

OBJECTIVE: To assess survival rates and clinical (pretreatment) prognostic factors in patients with clinically localized adenocarcinoma of the prostate. METHODS: Hospital cohort including 258 patients registered in the National Cancer Institute, in the city of Rio de Janeiro, southeastern Brazil, from 1990 to 1999. Five- and ten-year survival functions were estimated using the Kaplan-Meier estimator from the histological diagnosis (initial time of follow-up) to death due to prostate cancer (events). Prognostic factors were assessed using hazard ratios (HR) with confidence intervals of 95%, following the Cox's proportional hazards model. The assumption of proportionality of risks was tested using Schoenfeld residuals and the impact of outliers in the model fitness was analyzed using martingale and score residuals. RESULTS: Of 258 patients studied, 46 died during follow-up. The overall five-year and ten-year survival rates were 88% and 71%, respectively. A Gleason score higher than 6, PSA levels higher than 40 ng/mL, B2 stage, and white skin color were independent markers of poor prognosis. CONCLUSIONS: Gleason score, digital rectal examination and PSA levels have great predictive power and must be used in pretreatment risk stratification of patients with localized prostate cancer.