Longitudinal assessment of BMI in relation to ADT use among early stage prostate cancer survivors.

INTRODUCTION: The use of androgen deprivation therapy (ADT) for prostate cancer is on the rise, but its adverse side effects may include increased fat mass and decreased lean muscle mass. The net effect of ADT on BMI is unknown. METHODS: Primary, incident cases of early stage prostate cancer (n = 473) were identified from the Buffalo VA Medical Center tumor registry and matched to body size, demographic, comorbidity, and treatment exposure data from veteran medical records. Multilevel modeling was used to assess the association between ADT and changes in BMI. RESULTS: On average, survivors were overweight at diagnosis and showed small, non-significant changes in BMI over time. However, among those survivors with a history of ADT, a significant decrease of 0.05 BMI units per year was associated with each additional dose of ADT (p < 0.001). When the association between BMI rate of change and ADT was allowed to vary with respect to age, additional doses of ADT predicted stronger decreases in BMI for younger survivors as compared to older survivors (p < 0.05). Neither a history of surgery nor radiation influenced the association between ADT use and BMI. CONCLUSIONS: Declines in BMI in relation to ADT exposure may be reflective of unfavorable changes in body composition, especially decreased muscle mass, that is most pronounced in younger survivors. IMPLICATIONS FOR CANCER SURVIVORS: Survivors on ADT may benefit from close monitoring of physical functioning and referral for exercise interventions to preserve muscle mass and improve health related quality of life.