Physical Activity During Breast Cancer Therapy Associates With Preserved Exercise Capacity and Cardiac Function (WF97415).

Background: Cancer treatment increases cardiovascular disease risk, but physical activity (PA) may prevent cardiovascular disease.
Objectives: This study examined whether greater PA was associated with better submaximal exercise capacity and cardiac function during cancer therapy.
Methods: Participants included 223 women with stage I to III breast cancer (BC) before and 3 months after undergoing treatment and 126 control participants. Leisure-time PA (LTPA) was reported using the Godin-Shephard LTPA questionnaire. Cardiac function was assessed by cardiac magnetic resonance. Submaximal exercise capacity was determined by 6-minute walk distance.
Results: BC participants reported similar baseline LTPA scores (24.7; 95% CI: 21.7-28.0) as control participants (29.4; 95% CI: 25.0-34.2). The BC group declined to 16.9 (95% CI: 14.4-19.6) at 3 months relative to 30.8 (95% CI: 26.2-35.8) in control participants. Among BC participants, more LTPA was related to better exercise capacity (β ± SE: 7.1 ± 1.6; 95% CI: 4.0-10.1) and left ventricular (LV) circumferential strain (-0.16 ± 0.07; 95% CI: -0.29 to -0.02). Increased LTPA over the 3 months was associated with decreased likelihood of treatment-induced cardiac dysfunction according to LV circumferential strain classifications (OR: 0.98; 95% CI: 0.97-0.998). BC participants reporting insufficient LTPA according to PA guidelines exhibited deteriorations in exercise capacity (adjusted mean difference ± SE: -29 ± 10 m; P  = 0.029), LV end-systolic volume (5.8 ± 1.3 mL; P  < 0.001), LV ejection fraction (-3.2% ± 0.8%; P  = 0.002), and LV circumferential strain (2.5% ± 0.5%; P  < 0.001), but BC participants meeting LTPA guidelines did not exhibit these adverse changes.
Conclusions: PA declined during BC therapy; however, PA participation was associated with attenuated declines in exercise capacity and cardiac function that are often observed in this population. (Understanding and Predicting Breast Cancer Events After Treatment [WF97415 UPBEAT]; NCT02791581).
Competing Interests: Data collection was funded by the Wake Forest NCI Community Oncology Research Program (NCORP) Research Base grant 2UG1CA189824 with support of the NCORP. Additional funding for this study was provided by National Institutes of Health, National Cancer Institute grants R01CA199167 and T32CA093423. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(© 2023 The Authors.)