There is growing evidence that physical activity can help women with high-risk breast cancer survive longer.
The study indicated that women who were physically active before and after their cancer diagnosis were less likely than those not to have their cancer return (recur) or die.
The study was remarkable in that it collected data on the physical activity levels of women with high-risk breast cancer (cancer that is likely to recur or spread) at multiple time points—shortly before their diagnosis, throughout chemotherapy, and after treatment completion.
As a result, “there was still a survival benefit for women who [were] active but [didn’t exactly fulfill the standards,” said Dr. Cannioto.
According to Joanne Elena, Ph.D., M.P.H., of the Epidemiology and Genomics Research Program in the NCI’s Division of Cancer Control and Population Sciences (DCCPS), who was not involved in the study, these findings “provide evidence that physical activity at any point in time appears to be beneficial for breast cancer survivors.”
According to Kathryn Schmitz, Ph.D., M.P.H., an exercise oncology researcher at the Penn State College, breast cancer survivors can take matters into their own hands and improve their health and decrease their risk of death by becoming more physically active, exercise oncology researcher Kathryn Schmitz, Ph.D., M.P.H, who was not involved in the study.
Exercising in the Long Term
Researcher Christine Ambrosone, Ph.D. from Roswell Park Cancer Institute, and her team published their findings in the DELCaP project financed by the NCI and conducted by Ambrosone. The NCI-funded SWOG Cancer Research Network led a large clinical trial comparing alternative chemotherapy regimens for women with high-risk breast cancer. This study was part of that trial.
One thousand three hundred forty patients from the SWOG trial who also participated in the DELCaP investigation were analyzed by Dr. Cannioto and her colleagues. Before diagnosis, during treatment, and one and two years after enrolment, participants answered questionnaires about their level of recreational physical activity at each time point. There was a mean follow-up time of 89 months, with participants being tracked for up to 15 years or until death occurred (7.4 years).
Physical exercise and cancer outcomes have been linked in epidemiological studies, but many studies have relied solely on data obtained at a single point in time, according to Dr. Cannioto.
Researchers analyzed participant questionnaire responses to assess if they had completed the minimum 2018 Physical Activity Guidelines for Americans at each time point. According to the guidelines, adults should get 2.5 to 5 hours of moderate to vigorous physical activity each week, or 1.25 to 2.5 hours of strenuous to aerobic physical exercise.
Before and after diagnosis (after treatment), women with breast cancer who completed the minimum physical activity standards both times had a 55% reduced risk of their disease returning and a 68% reduced risk of death from any cause (not just breast cancer).
There was a 46% and 43% lower risk of recurrence or mortality among patients who followed the standards before diagnosis but not during follow-up, respectively, than those who did not meet the guidelines at both periods. “It’s never too late to begin exercising to get the benefits,” Dr. Elena stated.
Increasing Accuracy in Self-Reporting
In this study, researchers employed a lengthy questionnaire to gather information about how much physical activity people engage in, which is likely to be more reliable than a single question or a brief survey, “providing stronger credence to the findings.”
According to Richard Troiano, Ph.D., also of the DCCPS Epidemiology and Genomics Research Program, evaluating results based on whether or not participants met the physical activity guidelines rather than how many minutes of physical activity people completed each week is likely to reduce inaccuracies.
Studies like DELCaP and other epidemiologic studies that form the basis of the latest exercise guidelines for cancer survivors have limitations in that they cannot prove a cause-and-effect relationship between physical activity and improved survival or reduced risk of recurrence, Drs. Troiano and Elena said