Surgery Increases Survival for Patients With HER2-positive Stage 4 Breast Cancer

Surgery is associated with higher survival rates in patients with human epidermal growth factor receptor 2 (HER2)-positive stage 4 breast cancer compared with those who did not undergo surgery, according to findings presented at the American Association for Cancer Research (AACR) in Atlanta.

Study lead author Ross Mudgway, a third-year student in the University of California-Riverside School of Medicine, explained at the meeting that in recent years, most patients with HER2-positive stage 4 breast cancer are treated with systemic therapy, including chemotherapy, targeted therapy, or endocrine therapy.

"Surgery is sometimes offered to these patients, but previous research on whether surgery improves survival has yielded mixed results," he said in a press release.

HER2 status has been reported in large registry data sets since 2010, however, the impact of surgery on this type of breast cancer has not been well-documented across hospital systems, according to the press release.

In their study, the investigators used records from the National Cancer Database from 2010 to 2012 to conduct a retrospective cohort study of 3231 women with HER2-positive stage 4 breast cancer.

They found that 89.4% of the women had received chemotherapy or targeted therapies, 37.7% had received endocrine therapy, and 31.8% had received radiation. Overall, 1130 women (35%) received surgery.

The researchers found surgery was associated with a 44% increased chance of survival, assuming the majority also had systemic treatment. The study also found that women with Medicare or private insurance were more likely to have surgery and had a lower mortality risk for their disease than those with Medicaid or no insurance. White women were also more likely than non-Hispanic black women to have surgery and less likely to die of their cancer.

"These results suggest disparities in health care due to race and socioeconomic factors, and these must be addressed," Mudgway said.

According to Mudgway and senior author Dr. Sharon Lum, a professor in the Department of Surgery-Division of Surgical Oncology and medical director of the Breast Health Center at Loma Linda University Health, numerous factors may contribute to a physician's decision about whether to recommend surgery, including other chronic diseases in the patient, response to other forms of treatment, and overall life expectancy.

"Our findings should be considered in the context of all other factors," Mudgway said in the release. "For patients, the decision to undergo breast surgery, especially a mastectomy, can often be life- changing as it affects both physical and emotional health. The patient's own feelings about whether or not she wishes to have surgery should be considered."