National Cancer Database trends in surgical resection of the breast primary for stage IV breast cancer

Background: Survival benefit after resection of the breast primary for women with metastatic breast cancer reported in retrospective studies has not been uniformly confirmed by randomized controlled trials. To assess the need for dissemination of trial results by the ACS Cancer Research Program Dissemination and Implementation (ACS CRP D&I) committee, we analyzed trends and predictors of surgery and other therapies for stage IV breast cancer. Methods: The National Cancer Database (NCDB) was queried to identify women diagnosed with clinical stage IV breast cancer of ductal, lobular, or metaplastic histology between 2004 and 2017. Trends in utilization of breast surgery and other treatments and possible predictors of breast surgery were examined in univariable and multivariable analyses. Results: We identified 87,331 cases meeting inclusion criteria. Rates of surgical resection rose until 2009, peaking at 37%, then declined to a rate of 18% in 2017. The largest decline was seen in the hormone receptor positive (HR+), HER2 negative (HER2-) subgroup with up to 70% of patients undergoing surgery in 2007, down to 15% in 2017. In 2004, the rate of systemic therapy alone was slightly more common than locoregional therapy (surgery and/or radiation) with or without systemic therapy (48% vs 37%). However, by 2017, systemic therapy alone was by far more common (69% vs 20%). Conclusion: Rates of surgical resection of the breast primary for stage IV breast cancer have been on the decline in recent years, suggesting that providers at Commission on Cancer accredited hospitals are becoming more selective about who will be offered surgical resection.