Penn Study Tests Effects of Exercise for Reducing Breast Cancer Risk

While cancer research has come a long way in helping identify ways in which people can prevent certain types of cancer, cancer researchers are still looking for new, effective cancer prevention strategies.

Cancer researchers at Penn Medicine are testing to see if women who are at higher-than-average risk of developing breast cancer during their lifetimes may be able to reduce their risk with exercise. 
Research has already proven that female athletes have reduced estrogen levels as a result of exercise.   There is also evidence that lower estrogen levels can reduce breast cancer risk over a woman’s lifetime.  The hypothesis of the study is that if estrogen levels can be reduced through exercise, the risk of a future breast cancer diagnosis may be lower as well.

The Women in Steady Exercise Research (WISER) Sister project at Penn, is a five-year study for women at elevated risk of developing breast cancer. The study examines the effects of exercise on estrogen levels. Women in the WISER Sister study are asked to exercise a certain amount each week for about five months.  Their estrogen levels are measured before they start exercising and again during their final months of exercise in order to measure the amount of hormonal change.   

The research team is trying to learn how much exercise is necessary to reduce estrogen levels, as most women do not have hours each day to devote to exercise.  They are also exploring whether estrogen levels in the at-risk population respond differently than those in the average population.  If the researchers can prove this hypothesis, women at increased risk of developing breast cancer may have an alternative to conventional and often invasive prevention techniques.  The results of the study may provide those women with some additional time to carefully weigh their options before having to make any potentially difficult decisions.  

Even if enough data are gathered to prove the  hypothesis, it’s important to know that exercise is beneficial to “EVERY BODY.”  Exercise can help prevent the onset of a number of different chronic conditions such as type 2 diabetes and hypertension, and can be used as a means of treating countless others.  Women who exercise may be both physically and mentally healthier than those who do not.  Exercise also promotes synergy between the body and mind, and may give women the self-assurance and confidence they need to be mentally resilient and physically fit if they do face cancer. 

And women who use exercise to prevent cancer might experience an added benefit that everyone can wish for—the ability to fit into that smaller pair of jeans.

Watch Kathyrn Schmitz Ph.D., MPH, discuss more about the study.