Current status of endocrine therapy for prostate cancer in Japan - Analysis of primary androgen deprivation therapy on the basis of data vollected by J-CaP

Background: Based on the data of current status of endocrine therapy for prostate cancer registered in the Japan Study Group of Prostate Cancer (J-CaP), we conducted an analysis of primary androgen deprivation therapy (PADT) and an interim analysis of the prognosis. Methods: Of the 26 272 cases registered in the server of J-CaP, the 19 409 cases initially receiving PADT were included in this study. The initial therapy was divided into eight categories according to its features. Results: Of the 19 409 patients, 1513 (7.8%) were given anti-androgen monotherapy, 955 patients (4.9%) surgical castration only, 1001 patients (5.2%) surgical castration + anti-androgen, 3015 patients (15.5%) LHRH monotherapy, 1658 patients (8.5%) LH-RH + short-term anti-androgen, 10 434 patients (53.8%) LH-RH + anti-androgen, 37 patients (0.2%) watchful waiting and 796 patients (4.1%) other therapy. In progression-free survival, the prognosis was slightly better following maximum androgen blockade (MAB) in each stage. Conclusions: The pattern of PADT is more typical in Japan compared with that in the United States. Patients who received MAB accounted for 59.0% of all the patients. MAB tends to be more often selected for patients who are rated as being at high risk on the basis of high Gleason score or PSA level upon diagnosis in each clinical stage of the disease. Investigations of the outcome are on-going and they will make clear the significance of this trend in Japan.