A substantial number of older women may experience worsening frailty after undergoing surgery and radiation therapy for early-stage breast cancer, according to a new study.

About 1 in 5 experienced clinically significant deterioration in frailty status after treatment, the study team found. Women at highest risk for declines in frailty following treatment had “robust” baseline frailty status at diagnosis and underwent more invasive mastectomy compared with lumpectomy.

The fact that “robust” older women were more likely to become frail after locoregional therapy suggests that “thoughtful treatment decisions should be undertaken in all older women, not simply those who have frailty at diagnosis,” said the investigators, led by Christina Minami, MD, of Dana-Farber/Brigham and Women’s Cancer Center in Boston.

The study findings emphasize that there is no one-size-fits-all approach to breast cancer treatment in the elderly, said Sarah P. Cate, MD, director, Breast Surgery Quality Program, Mount Sinai Health System, New York, who wasn’t involved in the research. “Some patients will sail through a surgery, and others are severely affected by it.”

The study was published online in JAMA Surgery.

Given the growing number of older adults with breast cancer, understanding how age-related syndromes, such as frailty, may alter cancer outcomes and how cancer treatments change aging trajectories remains important.

To investigate, Dr. Minami and colleagues used Surveillance, Epidemiology, and End Results Medicare data to identify 31,084 women (mean age, 73) who had been diagnosed with ductal carcinoma in situ (DCIS) or stage I HR-positive, ERBB2-positive breast cancer and who underwent surgery (23% mastectomy, 77% lumpectomy) and radiation therapy.

Worsening frailty status was defined as a decline of 0.03 or greater in a validated frailty index from the time of diagnosis to 1 year. This level of change has been linked to greater mortality risk and greater cost of care.

Frailty status at diagnosis was “robust” in 56% of the women, prefrail in 40%, mildly frail in 4%, and moderately to severely frail in 0.3%.

According to the researchers, 21.4% of the women experienced clinically significant declines in their frailty status after treatment. These declines occurred in 25% of women who underwent mastectomy and 20% of those who underwent lumpectomy.

After adjusting for covariates, there was a higher likelihood of worsening frailty among women who were robustly frail at baseline, in comparison with those who were moderately to severely frail at baseline (odds ratio, 6.12), and in those who underwent mastectomy vs. lumpectomy (OR, 1.31).

Older age and race were also linked to worsening frailty status following treatment. Compared with younger women (aged 65-74 years), older women were more likely to experience worsening frailty (OR, 1.21 for women aged 75-79; OR, 1.53 for those aged 80-84; OR, 1.94 for those aged 85 and older). In addition, Black women were more likely than non-Hispanic White women to experience worsening frailty after treatment (OR, 1.12).

“Previous studies have documented lasting declines in functional status after surgery in older patients with breast cancer, but breast cancer treatment has not been implicated in worsening frailty to date,” Dr. Minami and colleagues explain. But “given the substantial proportion of women experiencing worsening frailty and the significant difference by breast surgery type, frailty status as a cancer therapy outcome should be further explored.” In addition, “tailoring locoregional therapy intensity in this population is important,” they write.

Dr. Cate explained that randomized clinical trials such as COMET and LORIS, which explore the monitoring of patients with DCIS in lieu of active treatment, “will likely make a big impact on this population, as we currently do not have randomized controlled data for observation of breast cancer.”

Dr. Cate added as well that assessing a patient’s ECOG [Eastern Cooperative Oncology Group] performance status is vital “to determine who can really tolerate a breast cancer surgery” and that opting for antiestrogens, such as aromatase inhibitors, which can keep cancer at bay for years, “may be preferable for many older patients.”

The study was funded by Brigham and Women’s Hospital’s Department of Surgery’s Beal Fellowship. Dr. Minami and Dr. Cate have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Surgery for early breast cancer can worsen frailty in older women