Androgen Deprivation Therapy on Bone Mineral Density Change in Prostate Cancer Patients

Objective: To determine the rate of bone mass loss induced by two therapeutic strategies of ADT (CAD versus IAD) in men with prostate cancer. Design, setting, and participants: the investigators will perform randomized, open label clinical trial. Men aged over 50 yrs old with prostate cancer (localized, locally advanced, metastatic prostate cancer) who are treated with primary ADT for newly diagnosed prostate cancer or salvage ADT at biochemical recurrence following radical prostatectomy will be included. Participants will be randomly assigned to one of the following treatment arms: Arm 1 (CAD): ADT without any discontinuation during study period (12 months). Arm 2 (IAD): ADT for the first 6 months of study period, if the prostate-specific antigen (PSA) reaches its nadir (\< 4 ng/dL) and serum testosterone reaches castration level (\< 50 ng/dL). Outcomes: Primary outcome: change of L-spine total BMD. Secondary outcomes: change of femur neck BMD, incidence rate of osteoporosis, risk of 10 year major osteoporotic fracture, quality of life based on Expanded Prostate Cancer Index (EPIC) questionnaire. Timing of outcome measurement: at baseline and up to 12 months after randomization. Statistical analyses: student's t test for continuous outcomes and Fisher's exact or chi-square test for dichotomous outcomes.