Treatment outcome by risk group after radical prostatectomy in Japanese men

Background: North American investigators have suggested the usefulness of risk-group stratification based on prostate-specific antigen (PSA), clinical stage and biopsy Gleason score for predicting the biochemical outcome of prostate cancer after radical prostatectomy. There have been no reports of the application of this stratification to early biochemical outcome after radical surgery in Japanese men. Methods: The study population consisted of 178 men treated with radical retropubic prostatectomy and bilateral pelvic lymph node dissection at Kitasato University Hospital (n = 110) and Kurashiki Central Hospital (n = 68) between October 1992 and May 1999. Pathologic and biochemical outcomes after radical prostatectomy were analyzed based on risk-group stratification. Risk groups were further analyzed according to detailed pathologic findings at biopsy. Results: The median follow-up period for the 178 patients after radical surgery was 41.5 months (range, 2.0-82.0 months; mean, 40.9 months). Fifty-eight patients experienced PSA failure at a median of 8.0 months following surgery (range, 0.0-58.0). Risk-group stratification distinctly defined groups of pathologic findings in the radical prostatectomy specimens. The proportion of patients with PSA failure for low, intermediate and high-risk groups were 9.5%, 23.9% and 56.9%, respectively (P < 0.0001). Use of the number of cores with cancer and maximum cancer length in biopsy cores failed to improve risk stratification for PSA outcome in all risk groups. Conclusions: Risk-group stratification based on preoperative variables may significantly improve a physician's ability to counsel patients about PSA outcome after radical prostatectomy. Further improvement in risk stratification may call for use of variables other than the pathologic information in biopsy cores.