Declines in physical function from androgen deprivation therapy (ADT) in men with nonmetastatic prostate cancer: A matched cohort study

Abstract

9526 Background: Although prolonged use of ADT is hypothesized to adversely affect physical function, few studies have examined this relationship longitudinally using objective measures of physical function. Methods: Men age 50+ with non-metastatic prostate cancer (PC) starting continuous ADT were enrolled in this prospective longitudinal matched cohort study. Physical function was assessed with the six-minute walk test (6MWT), grip strength, and the Timed Up and Go (TUG) test, representing endurance, upper extremity strength, and lower extremity strength, respectively. Self-reported physical function was measured with the Medical Outcomes Study SF-36. Assessments were done at baseline, 3 months, 6 months, and 12 months. Two control groups, matched on age, education, and baseline function were also enrolled. One control group had PC but did not receive ADT, and the other group did not have PC. Linear mixed effects regression models were fitted adjusting for baseline covariates. Results: 85 patients on ADT, 86 PC controls, and 86 healthy controls were enrolled. All 3 groups were similar in age (mean age 69.1 y, range 50–87) and physical function (all ANOVA p>0.05). The 6MWT distance improved in both control groups (p=0.05 and 0.05 for PC and healthy controls, respectively) but remained stable in the ADT group (p=0.96)). Grip strength declined in the ADT group (p=0.04), remained stable in the PC control group (p=0.31), and improved in the healthy control group (p=0.008). TUG scores remained stable over time and across groups (p>0.10). SF-36 physical function declined in the ADT group (p<0.001) but increased in both control groups (p<0.001). Negative effects on outcomes were noted within 3–6 months of starting ADT and were larger with older age. Conclusions: Endurance, upper extremity strength, and self-reported physical function are affected within 3–6 months of starting ADT, particularly in older men. Declines persist at 12 months after adjustment for baseline function and covariates. Exercise intervention studies to counteract these losses are warranted. No significant financial relationships to disclose.