Project 461482

Breast cancer is the most commonly diagnosed cancer among Canadian women. Due to advances in prevention, early detection and treatment, breast cancer mortality has decreased by 52% since 1984. A result of improved survival and aging of the population is that older (60 years or greater) breast cancer survivors (BCS) face a new set of health care challenges. Specifically, cardiovascular disease (CVD) is the leading cause of death in older BCS. A hallmark feature in older BCS is reduced functional capacity (measured as peak exercise oxygen uptake, VO2peak) that persists in the long-term period after completing chemotherapy. The mechanisms for the reduced VO2peak remain unknown, however may be due to abnormal cardiovascular and skeletal muscle function. Exercise training is an effective therapy to improve VO2peak, however older BCS who are at greatest risk for CVD have been underrepresented in exercise trials. Thus, the role of exercise training to improve VO2peak, cardiovascular and skeletal muscle function, skeletal muscle composition, physical function, CVD risk, and quality of life (QOL) in older BCS remain unknown. The aims of our proposed project are first to measure VO2peak, exercise cardiovascular and skeletal muscle function, skeletal muscle composition, physical function in older female BCS previously treated with anthracycline chemotherapy (1 year or greater) and healthy age-sex-CVD-matched controls. Second, we will examine the effects of exercise training versus usual care on VO2peak, cardiovascular and skeletal muscle function, skeletal muscle composition, physical function, CVD risk and QOL in older female BCS. After these aims are accomplished, we will have achieved the most comprehensive assessment of the mechanisms of impaired VO2peak and physical function and their improvement with exercise training in older anthracycline treated BCS. This project is also ideally suited to have a major impact on improving the health and wellbeing of older BCS.