Impact of advanced age on biochemical recurrence after radical prostatectomy in Japanese men according to pathological stage

摘要

Objective: To determine the impact of advanced age as a predictor of biochemical recurrence after radical prostatectomy in Japanese patients with regard to pathological stage. Methods: We retrospectively evaluated 379 Japanese patients with pT2-3N0/X prostate cancer undergoing radical prostatectomy from 2000 to 2010 at a single academic institution. Cox proportional hazards model was used to determine whether advanced age is a predictor of biochemical recurrence according to pathological stage. Results: The mean age at radical prostatectomy was 65.8 years. With a mean follow-up of 49.8 months, 61 men (16.1%) experienced biochemical recurrence. Martingale residual analysis showed that the adverse prognostic effect of age on biochemical recurrence fits a linear model, and patients were classified into two groups using a cut-off point of age 70 years. Although older patients had higher rates of biochemical recurrence than younger ones in the case of pT2 patients (P =0.049), advanced age itself was not an independent predictor of biochemical recurrence among the total cohort. However, especially in pT2 patients with negative surgical margins, advanced age was an independent predictor of biochemical recurrence (HR =3.97, P =0.006). In these patients, 2- and 5-year biochemical recurrence- free survival rates were 98.0 and 92.4% for younger patients and 93.2 and 82.0% for older patients, respectively (log-rank P =0.015). On the other hand, in pT3 patients, there was no significant association between age and biochemical recurrence.Conclusions: Advanced age is an independent predictor of biochemical recurrence after radical prostatectomy in Japanese patients with stage pT2 disease and negative surgical margins. Moreover, older patients of this group tended to have recurrence more than 2 years after surgery.