We evaluated patterns of surgical care and their association with overall survival among a contemporary cohort of women with stage IV breast cancer.

Surgical resection of the primary tumor remains controversial among women with stage IV breast cancer.

Women diagnosed with clinical stage IV breast cancer from 2003 to 2012 were identified from the American College of Surgeons National Cancer Database. Those with intact primary tumors who were alive 12 months after diagnosis were categorized by treatment sequence: (1) surgery before systemic therapy, (2) systemic therapy before surgery, and (3) systemic therapy alone. Multivariate logistic regression was used to estimate the association of treatment sequence with surgery type. Overall survival was estimated using multivariate Cox proportional hazards models.

Among 24,015 women, 56.2% (13,505) underwent systemic therapy alone and 43.8% (10,510) underwent surgical resection. Rates of surgery decreased slightly over time (43.1% in 2003 to 41.9% in 2011). Treatment with systemic therapy before surgery was associated with larger tumor size (median 4.5 vs 3.1 cm, P < 0.001) and receipt of mastectomy (81.4% vs 52.2%, P < 0.001) when compared to those who underwent surgery first. Receipt of surgery, whether before or after systemic therapy (Hazard Ratio, 0.68; 95% confidence interval, 0.62-0.73; Hazard Ratio, 0.56; 95% confidence interval, 0.52-0.61; P < 0.001), was independently associated with improved adjusted overall survival when compared to systemic therapy alone.

Surgical resection of the primary tumor occurs in almost half of women with stage IV breast cancer alive 1 year after diagnosis, and is increasingly occurring after systemic therapy. Coordinated multidisciplinary care remains highly relevant in the setting of metastatic breast cancer, where surgical decisions should be made on an individual basis and may affect survival in select women.