Radiotherapy for patients with localized hormone-refractory prostate cancer: Results of the Patterns of Care Study in Japan

OBJECTIVE To evaluate the clinical results of radiotherapy (RT) for patients with regionally localized hormone-refractory prostate carcinoma (HRPC). PATIENTS AND METHODS As part of a Patterns of Care Study in Japan, a nationwide survey was conducted of RT for patients with prostate adenocarcinoma. We reviewed the detailed information of 140 patients with regionally localized HRPC who received RT between 1996 and 1998, and between 1999 and 2001, in 117 randomly selected institutes in Japan. The median (range) age of the patients was 74 (51-94) years, and their tumours were defined as well (14), moderately (51) or poorly (54) differentiated, or of unknown differentiation (21). The median (range) interval between hormonal therapy (HT) and RT was 32.5 (1.1-168.4) months. Ninety-five patients had T3-4 tumours and 28 had regional lymph node metastases before treatment. The median (range) prostate-specific antigen levels before the initial HT and before RT were 35.0 (1.5-276) and 10.0 (0.06-760.3) ng-mL, respectively. External beam RT was administered, with a median total dose of 66 Gy; 70 patients (50%) received pelvic irradiation. RESULTS At a median follow-up of 20.7 months, the 5-year overall and clinical progression-free survival rates (95% confidence interval) were 48.1 (36-60)% and 36.7 (26-47)%, respectively. Although there were distant metastases in 46 patients, only six had local progression. There was late morbidity of grade ≥3 in six patients. CONCLUSION To the best of our knowledge, this study comprises the largest series of regionally localized HRPC treated with RT reported to date. RT might have a limited role for HRPC, because in most patients RT failed, with distant metastasis.