Chemotherapy for Breast Cancer May Raise Risk of Falls

March 4, 2011 -- Breast cancer treatments such as chemotherapy and hormonal therapy may affect the patients’ balance, increasing their risk of falls, a new study shows.

Researchers at the Oregon Health and Science University Knight Cancer Institute studied 59 postmenopausal breast cancer survivors who had received treatment with chemotherapy and hormonal therapy, which can cause bone loss.

According to the researchers, 58% of breast cancer survivors fell within the year prior to the study. That’s nearly double the 25% to 30% fall rate for adults over age 65 who live in residences, rather than institutions such as hospitals or assisted-living facilities. The researchers say 47% of the women fell within six months of joining the study.

Problems With Balance

“Our study is the first to consider how breast cancer treatment may increase fall risk by using a comprehensive set of objective measures of fall risk and by exploring mediators of the treatment-falls relationship,” study researcher Kerri M. Winters-Stone, PhD, says in a news release. “Our findings suggest that recently treated post-menopausal breast cancer survivors have higher rates of falling compared with population averages for community-dwelling older adults.”

She says “balance disturbances may explain how treatment could have contributed to falls” in the survivors of breast cancer.

Fifty-nine of 143 women who expressed an interest in the study enrolled and completed testing at the start and after six months. The average participant was 58 years old and overweight.

The researchers measured a comprehensive set of neuromuscular and balance characteristics that are known to be associated with falls. They found that only balance problems distinguished breast cancer survivors who fell from those who did not.

Inner Ear Changes

The study also suggests that balance problems may have been related to changes in the inner ear that were associated with undergoing chemotherapy. The inner ear contributes to balance as well as the sense of spatial orientation.

The researchers conclude that further studies are needed to identify treatments for balance problems in breast cancer survivors, as well as for visual problems.

The study is published in the April edition of the Archives of Physical Medicine and Rehabilitation.