[Predictability of Gleason score and reduction time (tau) of prostatic volume after castration for the prognosis of prostatic cancer].

PURPOSE The efficacy of the reduction time (tau) after castration as a prognostic factor was examined by comparing to Gleason score. MATERIALS AND METHODS The change of prostatic volume after castration was observed from the castration to 3 months after in 24 cases of prostatic cancer. Prostatic volume was examined by transrectal ultrasonography of the prostate. Survival curves was calculated by Kaplan-Meier method. Differences among survival curves were analyzed using Cox-Mantel test. RESULTS tau had a close relationship to the prognosis of each case (Wilcoxon test: p < 0.05, Cox-Mantel test: p < 0.05). Gleason score had a weak relationship to prognosis (Wilcoxon test: N. S., Cox-Mantel test: p < 0.05). CONCLUSIONS tau was efficient as prognostic factor compared to Gleason score.