BackgroundThis prospective observational study elucidated the usefulness of hormonal therapy for localized prostate cancer. Background factors and the health-related quality of life in patients who initially underwent radical prostatectomy (RP) or primary androgen deprivation therapy (PADT) for localized prostate cancer are summarized.Materials and methodsPatients aged 67–76 years with clinical stage T1c or T2 localized prostate cancer treated with PADT or RP, a prostate-specific antigen concentration of <20 ng/mL, and Gleason score of ≤7 were included. Health-related quality of life results estimated by the Medical Outcomes Study 8-Item Short-Form Health Survey (SF-8) and the Expanded Prostate Cancer Index Composite (EPIC) were investigated.ResultsIn total, 850 patients who underwent RP and 370 patients who underwent PADT were enrolled. The proportion of patients with comorbidities of hypertension, cardiovascular disease, and/or cerebrovascular disease was greater in the PADT group than in the RP group. The proportion of patients deciding on treatment was significantly higher in the PADT group than in the RP group. In the RP group, the scores of many SF-8 and EPIC domains decreased at 3 months following surgery and returned to baseline levels at 1 year. In the PADT group, several domains gradually decreased during the year after treatment initiation. The proportion of patients with decreased satisfaction scores at 1 year compared with baseline was lower in the PADT group than that in the RP group.ConclusionTreatment risk influenced decisions on primary treatment for localized prostate cancer. Although there was a selection bias, short-term overall satisfaction in the PADT group was superior to that in the RP group in this clinical study.