Exercise Crucial for Breast Cancer Survivors on Hormone Therapy

New research suggests that exercise may reduce side effects experienced by breast cancer survivors undergoing treatment with aromatase inhibitors.

Many patients treated for breast cancer are administered aromatase inhibitors, which are hormone-therapy drugs that stop estrogen production.

The investigators found that resistance and aerobic exercise may prevent side effects from these drugs, and improve patient outcomes due to weight loss, according to a study published by Obesity Journal.

Although aromatase inhibitors (AIs) can significantly reduce the likelihood of breast cancer recurrence, patients may experience bone loss or joint pain (arthralgia). As a result of these adverse events, approximately 40% of patients discontinue treatment before they are directed to.

“When women quit taking AIs, they increase the chances of their breast cancer reoccurring,” said study co-author Gwendolyn Thomas, PhD. “If breast cancer survivors are obese or overweight, they are likely to experience arthralgia. Interventions that address obesity in women taking AIs can help them continue this necessary treatment.”

The research team was comprised of individuals from Syracuse University, Yale University, Columbia University, Penn State, and the Dana-Faber Cancer Institute, and was funded by the National Institutes of Health. This was the first study to examine the effects of exercise in postmenopausal patients who survived breast cancer.

For 1 year, all patients participated in 2 weight training sessions, and 150 minutes of moderate aerobic activity each week. The researchers recorded body composition for each patient, which included body mass index, percent body fat, lean body mass, and bone mineral density, according to the study.

“We noticed a drop in percent body fat and body mass index, as well as a significant increase in their lean body mass,” Dr Thomas said. “These changes have clinical benefits, but also suggest that exercise should be prescribed in conjunction with AIs, as part of a regular treatment regimen.”

The researchers noted that approximately 65% of breast cancer survivors are overweight or obese, and are at an increased risk of experiencing adverse health events. These patients rely on hormone therapy, since it may prevent hormone receptor-positive disease from returning. However, hormone treatments like AIs may put them at risk for comorbidities, such as significant weight gain.

“These changes put women at risk for frailty fractures and osteoporosis, not to mention further risk for comorbid chronic disease and cancer reoccurrence,” Dr Thomas said.

The investigators found that a majority of the study participants were white and highly educated. Participants indicated that they typically did not exercise for more than 1 hour per week before the study.

“There are so many barriers to exercise in everyday life,” Dr Thomas said. “We can tell our patients they need to exercise, but helping them meet their goals is something at which we [as exercise scientists] need to do a better job.”

The researchers plan to create new ways to help breast cancer survivors increase physical activity levels. Dr Thomas is currently recruiting participants for a related project to create a fitness application for these patients, according to the study.

“I’m really excited about this project because it will enable graduates and undergraduates to engage in patient-oriented intervention research,” Dr Thomas concluded. “By using a mobile platform for health promotion and behavior change, we can make exercise more accessible to breast cancer survivors, especially those who take inhibitors and struggle with obesity or being overweight.”