The impact of physical activity on fatigue and quality of life during and after adjuvant treatment for breast cancer

BACKGROUND Although physical activity (PA) can alleviate fatigue and improve quality of life (QoL) in patients with breast cancer (BC), not all domains of PA may have equal impact. The objective of the current study was to examine the longitudinal impact of PA components on the evolution of fatigue and QoL during and after adjuvant treatment for BC. METHODS The women included in the study were participants in the 2‐year longitudinal FATSEIN (“Fatigue dans le cancer du Sein”) study. Fatigue and QoL were measured using the Multidimensional Fatigue Inventory and the European Organization for Research and Treatment of Cancer 30‐item QoL questionnaire, respectively. Group‐based trajectory analysis was used to determine patterns of PA evolution (frequency, duration, and intensity). Cross‐sectional and longitudinal associations between PA patterns and fatigue and QoL were analyzed by using multivariable linear regression and a mixed model. RESULTS Among the 424 women who were included (mean ± standard deviation age, 57.1 ± 10.4 years), 2 trajectories were identified for each of the 3 PA components: low and insufficient frequency (51.2%) or regular and moderate frequency (48.8%), low and insufficient duration (47.6%) or regular and moderate duration (52.4%), and low intensity (47.2%) or low to moderate intensity (52.8%). Overall, during treatment, fatigue was increased and QoL was decreased, and the reverse was observed after treatment. During treatment, increased fatigue and decreased QoL were limited by regular PA frequency (β = −8.71 for total fatigue; β = 14.59 for emotional function), but the results were less significant after treatment. CONCLUSIONS PA, especially its frequency, is an important determinant of fatigue and QoL during adjuvant treatment for BC. The promotion of regular PA among women who are receiving treatment for BC may be an effective way to reduce fatigue and improve QoL. Cancer 2018;124:797‐806. © 2017 American Cancer Society. The frequency of physical activity is an important determinant of fatigue and quality of life during adjuvant treatment for breast cancer. Promoting regular physical activity among women undergoing treatment for breast cancer may be an effective way to reduce fatigue and improve quality of life.