Physical activity before, after breast cancer treatment ‘consistently associated’ with improved survival
Physical activity before and after breast cancer treatment appeared associated with significant reductions in recurrence and mortality rates among a cohort of patients with high-risk disease, according to study results published in Journal of the National Cancer Institute.
Researchers additionally found that patients who consistently engaged in lower volumes of physical activity on a regular basis — including before, during and after treatment — experienced survival advantages similar to those who met and exceeded HHS’s Physical Activity Guidelines for Americans.
“Additional evidence is mounting to show a strong association between post-diagnosis physical activity and breast cancer outcomes, demonstrating the potential therapeutic benefit of exercise as a part of comprehensive patient and survivorship care,” Rikki A. Cannioto, PhD, EdD, researcher in the department of cancer prevention and control at Roswell Park Comprehensive Cancer Center, told Healio. “We also found that survivors did not need to exercise at the highest levels to experience a similar survival advantage, which is particularly encouraging given that patients and survivors may be overwhelmed by the most current guidelines recommending 150 to 300 minutes per week of moderate-intensity recreational physical activity or 3 days per week of 30 minutes or more of moderate-intensity structured aerobic exercise for cancer survivors.”
Cannioto and colleagues sought to assess the effect of physical activity before and after breast cancer diagnoses among 1,340 patients included in the questionnaire-based Diet, Exercise, Lifestyle and Cancer Prognosis (DELCaP) study, which supported the randomized phase 3 SWOG S0221 trial. They collected data on physical activity before breast cancer diagnosis, during treatment and at 1- and 2-year intervals after study enrollment.
Patients were grouped according to whether they met the minimum physical activity guidelines and classified as inactive, low-active, moderate-active or high-active.
As expected, researchers observed decreases in physical activity among patients during treatment. More than half (54.5%) of patients reported regular recreational physical activity during treatment, compared with 73.2% before breast cancer diagnosis, The highest prevalence of physical activity (75.1%) occurred at the 2-year follow-up.
Results of joint-exposure analyses showed patients who met the activity guidelines before and 1 year after breast cancer diagnosis experienced a statistically significant decrease in hazard for recurrence (HR = 0.59; 95% CI, 0.42-0.82), as well as for mortality (HR = 0.51; 95% CI, 0.34-0.77). These associations appeared more pronounced at the 2-year follow-up (HR for recurrence = 0.45; 95% CI, 0.31-0.65; HR for mortality = 0.32; 95% CI, 0.19-0.52).
“Evidence suggested that patients who were not meeting the guidelines before diagnosis, but who consistently met the guidelines at 2-year follow-up, experienced significantly reduced risk for recurrence and mortality,” Cannioto told Healio. “These findings have important implications in the clinical oncology setting because they suggest that a cancer diagnosis may serve as an impetus for increasing physical activity in some patients, and among these patients, beginning an exercise program after treatment completion resulted in a survival advantage.”
Results of time-dependent analyses, in which researchers factored in activity from all time points, showed significant reductions in hazard for mortality among patients categorized as low-active (HR = 0.41; 95% CI, 0.24-0.68), moderate-active (HR = 0.42; 95% CI, 0.23-0.76) and high-active (HR = 0.31; 95% CI, 0.18-0.53).
“The strong inverse relationship between pre-diagnosis recreational physical activity and outcomes among those meeting the recommended range of activity reveals the broader health impact of these findings by suggesting that, even though exercise may not prevent breast cancer in all women, it is consistently associated with a survival advantage,” Cannioto told Healio. “Our group recently received funding to conduct a randomized pilot study to further explore the underlying biological mechanisms linking physical activity with improved outcomes among breast cancer survivors.” – by Jennifer Southall
For more information:
Rikki A. Cannioto, PhD, EdD, can be reached at Roswell Park Comprehensive Cancer Center, Elm & Carlton streets, Buffalo, NY 14263; email: email@example.com.
Disclosures: The study was funded by NCI grants, the Breast Cancer Research Foundation and Amgen Inc. Cannioto reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.