Regional and facility disparities in androgen deprivation therapy for prostate cancer from a multi-institutional Japan-wide database

Objectives: To examine the differences in prognosis of prostate cancer patients receiving primary androgen deprivation therapy by region and facility type using a Japan-wide database. Methods: Data on patients treated with primary androgen deprivation therapy between 2001 and 2003 from a nationwide community-based database established by the Japan Study Group of Prostate Cancer were obtained. Clinicopathological characteristics and prognostic variables, including progression, cancer-specific survival and overall survival, were compared according to region and facility type where the patients were treated. Results: Among 19 162 patients, 7102 (37.1%) and 12 060 (62.9%) men were in urban and rural areas, respectively, and 3556 (18.6%), 13 623 (71.1%) and 1983 (10.3%) patients were enrolled from academic centers, non-academic hospitals and urological clinics, respectively. The risks of progression, cancer-specific mortality and all-cause mortality were comparable between urban and rural areas in propensity-score matched analysis. Risks of progression, cancer-specific mortality and all-cause mortality in urological clinics were higher than those in academic centers in propensity-score matched analysis. Conclusions: Our findings suggest that Japan facility type, but not geographical regions, might affect the prognosis of prostate cancer patients receiving primary androgen deprivation therapy.