General surgery

Surgery was associated with higher survival rates for patients with HER2-positive (HER2+) stage 4 breast cancer compared with those who did not undergo surgery, according to results presented at the AACR Annual Meeting 2019, March 29-April 3. Between 20 and 30% of all newly diagnosed stage 4 breast cancer cases are HER2+, explained the study’s lead author, Ross Mudgway; a medical student at the University of California, Riverside School of Medicine.

Improved survival

This form of breast cancer once had poor outcomes, but in recent years, advances in targeted therapy; such as trastuzumab (Herceptin), have led to improved survival. In recent years, most patients with HER2+ breast cancer is treat with systemic therapy, which could include chemotherapy; targeted therapy, or hormonal therapy, Mudgway said. Surgery is sometimes offer to these patients; but previous research on whether surgery improves survival has yielded mixed results, he said.

Mudgway and senior author Sharon Lum, MD, professor in the Department of Surgery-Division of Surgical Oncology and medical director of the Breast Health Center; Loma Linda University Health, noted that HER2 status is report in large registry data sets since the early 2000s; but the impact of surgery on this type of breast cancer is not document across hospital systems.

To assess the impact of primary tumor resection on survival in HER2+ stage IV breast cancer patients, they conducted a retrospective cohort study of 3,231 women with the disease; using records from the National Cancer Database from 2010 to 2012. Of these women; 89.4% had received chemotherapy or targeted therapies; 37.7% had received endocrine therapy, and 31.8% had received radiation. Overall, 1,130 women, or 35%, received surgery.

Private insurance

The researchers found that surgery was associated with a 44%  increased chance of survival, assuming the majority also had systemic treatment. “This suggests that, in addition to standard HER2 targeted medications and other adjuvant therapy, if a woman has stage 4 HER2+ breast cancer; surgery to remove the primary breast tumor should be considered;” said Lum.

The study also examined factors associated with receipt of surgery and found that women with Medicare or private insurance were more likely to have surgery and less likely to die of 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.

Socioeconomic factors

“These results suggest disparities in health care due to race and socioeconomic factors, and these must be addressed;” Mudgway said. Mudgway and Lum said numerous factors may contribute to a physician’s decision on whether to recommend surgery, including comorbidities; response to other forms of treatment; and overall life expectancy.
They says these findings are consider in the context of all other factors. “For patients, the decision to undergo breast surgery, especially a mastectomy, can often be life-changing as it affects both physical and emotional health;” Mudgway said. “The patient’s own feelings about whether or not she wishes to have surgery should be considered.”