Radiotherapy for isolated serum prostate specific antigen elevation after prostatectomy for prostate cancer.

PURPOSE Elevated serum prostate specific antigen (PSA) may be the initial and only indication of disease recurrence after prostatectomy for prostate cancer. External beam radiotherapy may be given in this setting in an attempt to eradicate the disease but therapeutic outcomes after this approach require further description. We describe the intermediate term outcome in a large group of patients treated with radiotherapy and identify pre-therapy factors associated with disease outcome. MATERIALS AND METHODS We retrospectively studied a cohort of 166 consecutive patients treated with radiotherapy between July 1987 and May 1996. The Kaplan-Meier method was used to describe patient outcome for the overall study group, and statistical associations of pre-therapy variables with outcome were sought to identify predictive factors. RESULTS At a median followup of 52 months 46% (95% confidence interval 38 to 55) of patients were expected to be free of biochemical relapse 5 years after radiotherapy. Multivariate analysis identified pathological classification (seminal vesicle invasion), tumor grade and preradiotherapy serum PSA as independent factors associated with biochemical relapse. Although in 1 of 6 patients a chronic complication was attributed to radiotherapy, it was often mild and self-limited in nature. CONCLUSIONS In our current series approximately half of the patients treated with radiotherapy for an isolated elevation of serum PSA after prostatectomy were free of biochemical relapse at 5 years of followup. Radiotherapy may be given in this setting with modest long-term morbidity.