Physical activity and sexual functioning after radiotherapy for prostate cancer: Beneficial effects for patients undergoing external beam radiotherapy

Objectives. To evaluate, in a cross-sectional study, the relationships among physical activity, sexual functioning, and treatment type for 11 1 men who had undergone radiotherapy for localized prostate cancer within the past 18 months. Physical activity preserves the sexual functioning capacity of older men. However, little information exists regarding the association of physical activity with sexual functioning after treatment for localized prostate cancer. Methods. We tested the main effects of physical activity and treatment procedure, as well as their interaction, using hierarchical regression analysis. We hypothesized that greater physical activity would relate to better reported sexual functioning and that this relationship would be moderated by the type of medical treatment. Results. After controlling for age, medical comorbidity, fatigue, and urinary and bowel functioning, more physical activity was significantly associated with better sexual functioning, and the interaction of physical activity and treatment procedure added a significant amount of explained variance. Overall, 35% of the variance in sexual functioning was accounted for by the model. Post hoc tests of moderation revealed that men who underwent external beam radiotherapy had significantly greater sexual functioning scores as physical activity increased but the effect of physical activity on sexual function after brachytherapy and combination therapy was nonsignificant. Conclusions. Physical activity was positively correlated with sexual functioning for those who underwent external beam radiotherapy. These relationships should be replicated and explored in a larger, longitudinal sample to ascertain whether the effects of physical activity in this at-risk population extend over time and protect men from treatment-related decrements in sexual functioning. (c) 2005 Elsevier Inc.