Exercise Pre-Diagnosis for Breast Cancer Lowers Cardiovascular Event Risk

Exercise prior to a diagnosis of breast cancer was associated with a reduction in long-term cardiovascular events, according to a recent analysis.

Researchers publishing in recently-launched JACC CardioOncology, noted that “cardiovascular disease (CVD) is the leading nonmalignant cause of death in patients with cancer, and it is the leading cause of death in women with primary breast cancer who are older than 65 years of age.” To assess the risks, researchers for the prospective study looked at 4,015 women with confirmed primary breast cancer diagnosis who were enrolled in the Women’s Health Initiative. Participants completed questionnaires assessing leisure activity, physical activity (exercise) in terms of metabolic equivalent task (MET) hours per week (h/week). The study authors then used Cox proportional hazards models to estimate associations between pre-diagnosis exercise activity and onset cardiovascular events (heart failure (HF), myocardial infarction (MI), angina, coronary revascularization, peripheral arterial disease, carotid artery disease, transient ischemic attack, and cardiovascular death). Median follow-up was 12.7 years for CVD and 8.2 years for cardiovascular events.

According to the results, there were 324 cardiovascular events (89 MIs, 49 new HF  diagnoses, and 215 cardiovascular deaths). Multivariable analysis indicated that composite cardiovascular event incidence decreased across MET h/week categories (P=0.016). When compared with <2.5 MET h/week, hazard ratios were 0.80 (95% CI, 0.59 to 1.09) for the range between 2.5 and <8.6 MET h/week; 0.9 (95% CI, 0.64 to 1.17) for the range between 8.6 to <18 MET h/week; and 0.63 (95% CI, 0.45 to 0.88) for ≥18 MET h/week.

Essential for Long-term Care

“Pre-diagnosis exercise exposure may be a strategy to lower CVD risk in patients with primary breast cancer,” the authors wrote in their conclusion. “These findings add to the growing evidence highlighting the importance of exercise to manage cancer treatment-related acute and chronic late effects in the large and growing number of cancer survivors.”

In an accompanying editorial, authors Lindsey L. Peterson, MD, of the Washington University School of Medicine, and Jennifer A. Ligibel, MD, of the Dana-Farber Cancer Institute at Harvard Medical School, emphasized the role of exercise in long-term treatment.

“As more and more patients survive their breast cancer, cardiovascular disease is and will continue to become a major risk of morbidity and mortality for survivors,” they wrote. “Finding strategies to help patients engage in recommended amounts of physical activity before and after a breast cancer diagnosis will be critical to improving outcomes in women with early breast cancer, in particular in the rising number of older adults with breast cancer.”