Postoperative radiotherapy for patients with prostate cancer in Japan; changing trends in national practice between 1996-98 and 1999-2001: Patterns of Care Study for prostate cancer

Objective: To evaluate the changing trends of standards and practices for postoperative radiotherapy (RT) for patients with prostate cancer in Japan. Methods: The Japanese Patterns of Care Study (PCS) conducted a national survey in 84 institutions from 1996 to1998 (PCS96-98) and 76 institutions from 1999 to 2001 (PCS99-01). Detailed information relevant to RT was collected on a total of 169 patients (64 from 1996 to1998 and 105 from 1999 to 2001) with prostate cancer who had undergone radical prostatectomy. Results: The fraction of clinical T3-4 tumours before prostatectomy decreased from 63% in the period 1996-98 to 26% in the period 1999-2001 (P = 0.0004). The pre-RT prostate-specific antigen level was significantly lower in 1999-2001 than in 1996-98 (P = 0.0002). We did not find a significant difference in the percentage of patients who received pelvic irradiation in the time periods between PCS96-98 and PCS99-01 (P = 0.18). Although the median radiation doses of 60 Gy were not changed between the surveys, various doses (from 20 to 74.6 Gy) were delivered to the prostatic bed. In the 1999-2001 survey, 73 of 105 patients received a median dose of 56 Gy in an adjuvant setting, while the other 32 received a median dose of 60 Gy in a salvage setting (P = 0.0015). Conclusion: These data suggest that consensus has not been reached on the practice and management of postoperative RT for patients with prostate cancer in Japan.