Postradiotherapy 2-year prostate-specific antigen nadir as a predictor of long-term prostate cancer mortality.

Overview

PURPOSE: To report the influence of posttreatment prostate-specific antigen (PSA) nadir response at 2 years after external beam radiotherapy (RT) on distant metastases (DM) and cause-specific mortality (CSM). METHODS AND MATERIALS: Eight hundred forty-four patients with localized prostate cancer were treated with conformal RT. The median duration of follow-up was 9.1 years. A fixed landmark time point at 2 years was used to assess the influence of nadir PSA value as a time-dependent variable on long-term outcomes. RESULTS: Multivariate analysis demonstrated that nadir PSA