Physical Activity During Breast Cancer Therapy and CV Health
- Commonly used breast cancer treatments (anthracycline-based chemotherapy and chest radiotherapy) have cardiotoxic side effects that increase CV risk and incidence of morbidity and mortality related to CV events among stage I-III breast cancer.
- Moderate-strenuous physical activity may preserve exercise capacity and cardiac function among women undergoing breast cancer treatment.
- Assessment of LV circumferential strain may provide earlier detection of LV dysfunction to guide clinical management of cancer and/or cardioprotective therapies.
Can physical activity during the first 3 months of breast cancer therapy preserve the exercise capacity and cardiac function among women with stage I-III breast cancer?
This multicenter prospective study followed 223 women with stage I-III breast cancer at baseline and 3 months after undergoing treatment and compared to 126 controls. Physical activity levels were self-reported using the Godin-Shephard leisure-time physical activity questionnaire. Cardiac function (left ventricular [LV] ejection fraction, LV end-systolic volume, LV end-diastolic volume, LV circumferential strain %) was assessed by cardiac magnetic resonance. Submaximal exercise capacity was determined by 6-minute walk distance (6MWD).
Both breast cancer and control groups reported similar levels of physical activity at baseline (24.7 ± 0.03 vs. 29.4 ± 0.05, p = 0.16), but at 3 months, the breast cancer group levels declined to 16.9 (14.4-19.6) versus 30.9 (26.2-35.8) in controls (p < 0.001, d = 0.53). At 3 months, 6MWD of breast cancer participants declined by 22.5 m, which is considered a major decline for heart failure. Active breast cancer women with greater total weekly physical activity levels were associated with higher submaximal exercise capacity (7.1 ± 1.6 m, 4.0-10.1), and demonstrated preserved LV circumferential strain values over the 3 months were associated with decreased likelihood of treatment-induced cardiac dysfunction according to LV circumferential strain classifications (odds ratio, 0.98; 95% confidence interval, 0.97-0.998). Breast cancer participants reporting insufficient physical activity exhibited worsening exercise capacity (adjusted-mean difference ± standard error: -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).
Physical activity declined over the first 3 months of stage I-III breast cancer therapy; however, maintaining moderate-strenuous levels of physical activity prevents deterioration in exercise capacity and cardiac function that are often observed while receiving anthracycline-based chemotherapy (anthra-bC) and chest radiotherapy. Women maintaining higher physical activity levels also demonstrated preserved LV circumferential strain values and were less likely to meet criteria for subclinical LV dysfunction.
Increasing physical activity in women with stage I-III breast cancer receiving cancer treatment was an important therapeutic method for the prevention of CV disease. This study found that women with stage I-III breast cancer performing moderate-strenuous physical activity during the first 3 months of breast cancer treatment mitigated the progression of reduced exercise capacity and cardiac dysfunction often associated with the cardiotoxic effects of breast cancer treatments. In addition to assessment of physical activity levels by self-reports and 6MWD, monitoring LV circumferential strain may provide earlier detection of LV dysfunction, which has important implications for guiding clinical decisions regarding administration of cancer therapies and cardioprotective agents over longer courses of treatment.
Clinical Topics: Cardio-Oncology, Diabetes and Cardiometabolic Disease, Heart Failure and Cardiomyopathies, Prevention, Acute Heart Failure, Exercise
Keywords: Anthracyclines, Breast Neoplasms, Cardiotonic Agents, Cardiotoxicity, Exercise, Heart Failure, Leisure Activities, Patient Care Team, Secondary Prevention, Stroke Volume, Ventricular Dysfunction, Left
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