Impact of the Society of Surgical Oncology-American Society for Radiation Oncology Margin Guidelines on Breast-Conserving Surgery and Mastectomy Trends

Abstract

Background: In 2014, the Society of Surgical Oncology and American Society for Radiation Oncology guidelines defined negative margin for stage I and II breast cancer as "no tumor on ink." We hypothesized that repeat operation rates have decreased since the guideline introduction and would be associated with changes in overall surgical trends.

Study design: The National Cancer Database was used to identify women who underwent initial breast-conserving surgery (BCS) for stage I and II breast cancer from 2004 to 2015.

Results: Of 521,578 patients that underwent initial BCS, 82.7% had BCS alone and 17.3% had repeat operation: 67% with BCS followed by another BCS, 24% with BCS followed by unilateral mastectomy, and 9% with BCS followed by bilateral mastectomy (BM). The repeat operation rate decreased from 16.2% in 2004 to 14.0% in 2015 (p < 0.01). Breast-conserving surgery with repeat BCS decreased from 12.8% to 9.7%, and BCS followed by BM increased from 0.7% in 2004 to 1.9% 2013, then decreased to 1.4% in 2015. Trends for all surgical patients regardless of initial procedure showed a BCS rate of 64.0% in 2013 that increased to 67.6% in 2015. The BM rate increased from 4.6% in 2004 to 13.6% in 2013, then decreased to 12.8% in 2015 (p < 0.05). Adjusted multivariable regression found independent predictors of repeat operation to be diagnosis before 2014 (odds ratio [OR] 1.25), age younger than 50 years (OR 1.70), Her2neu receptor-positive tumors (OR 1.61), and lobular histology (OR 1.61).

Conclusions: Repeat operation rates are decreasing after 2014, which is also associated with a rise in BCS and decrease in BM rates. Dissemination of margin guidelines for early-stage breast cancer might be impacting overall surgical trends.