Relationship of objectively measured physical activity and sedentary behaviour with health-related quality of life among breast cancer survivors

BACKGROUND: Lack of physical activity throughout one’s lifetime has been associated with obesity and it is also an important risk factor of breast cancer. This study aimed to determine the relationship between objectively measured physical activity and sedentary behaviour with health-related quality of life (HRQoL) among breast cancer survivors in the East Coast region of Peninsular Malaysia. METHODS: A cross-sectional study involving 83 breast cancer survivors was carried out in two main government referral hospitals in the region. Participants wore the ActivPAL3™ microdevice physical activity monitor for seven consecutive days. The validated European Organization for Research and Treatment of Cancer Quality of Life Questionnaires (EORTC QLQ–C30) and Breast Cancer Supplementary Measure (EORTC QLQ-BR23) were used to measure their HRQoL. Multiple linear regression analysis was conducted to determine the relationship between objectively measured physical activity and sedentary behaviour with HRQoL. RESULTS: Longer time spent on moderate to vigorous physical activity (MVPA) was significantly associated with an improvement of HRQoL (p = 0.039) whereas longer time spent on sedentary behaviour significantly reduced the functioning score (p = 0.005). In addition, prolonged sedentary bouts were also significantly associated with better body image that led to improved HRQoL (p = 0.013). CONCLUSIONS: The study findings suggest that an increase in the time spent on MVPA was associated with improved HRQoL while sedentary behaviour was associated with poorer HRQoL among breast cancer survivors. Thus, it is essential to displace sedentary behaviour with MVPA to improve the quality of life of breast cancer survivors.