A combination of resistance and aerobic exercise may lessen the side effects of aromatase inhibitors enough to keep breast cancer patients on this therapy, and certainly improves their overall health, researchers reported.
The study, “The effect of exercise on body composition and bone mineral density in breast cancer survivors taking aromatase inhibitors,” was published in the Obesity Journal.
Aromatase inhibitors (AIs), which lower estrogen production, are commonly used as an adjuvant therapy (given before surgery) in breast cancer treatment, especially in postmenopausal women with estrogen receptor-positive cancer.
AIs are known to reduce the risk of breast cancer recurrence. But they can lead to severe side effects, such as bone loss or severe joint pain (arthralgia). Research has shown that nearly 40 percent of breast cancer survivors quit taking AIs before the end of their recommended five-year use.
Gwendolyn Thomas, assistant professor of exercise science at Syracuse University, and colleagues at Yale, Penn State, Columbia, and the Dana-Faber Cancer Institute in Boston examined the effects of 12 months of aerobic and resistance exercise, compared to usual care, on changes in body composition in postmenopausal breast cancer patients taking AIs.
In the Hormones and Physical Exercise (HOPE) trial (NCT02056067), a study funded by the National Institute of Health (NIH), 121 of these women were randomized to either supervised twice-weekly resistance exercise training and 150 minutes of weekly aerobic exercise, or to usual care (health education) for a full year. All participants had used AIs for at least six months prior to the study’s start and were experiencing at least mild arthralgia.
X-ray scans of participants were taken at baseline, and then at six and 12 months after starting the exercise program or usual care, to assess changes in body mass index, body fat, lean body mass, and bone mineral density.
At 12 months, the exercise group showed a significant increase in lean body mass, and a decrease in percent body fat compared to those treated with usual care. But no significant changes were seen in bone mineral density.
“When women quit taking AIs, they increase the chances of their breast cancer reoccurring,” Thomas said in a news release. “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.
“We noticed a drop in percent body fat and body mass index, as well as a significant increase in their lean body mass,” Thomas, who holds a PhD in kinesiology, added. “These changes have clinical benefits, but also suggest that exercise should be prescribed in conjunction with AIs, as part of a regular treatment regimen.”
Most study participants were doing no more than 55 minutes of exercise per week before its start.
With support from a fellowship from the Patterson Foundation, Thomas is looking to develop a fitness app for breast cancer survivors, and currently recruiting participants for this project.