Reasons for Re-Excision After Lumpectomy for Breast Cancer: Insight from the American Society of Breast Surgeons MasterySM Database

Background. There is marked variability of re-excision rates after initial lumpectomy for breast cancer. Reasons for re-excision and variability across surgeons have not been well documented. We hypothesized the American Society of Breast Surgeons (ASBrS) Mastery(SM) Program can identify reasons for re-excision. Methods. Data from January 1 to 7 November 2013 were evaluated in the ASBrS Mastery(SM) Program to determine re-excision lumpectomy rate (RELR). On 1 June 2013, a tool to track reasons for re-excision was developed. Variation in re-excision rate by surgeon and patient characteristics was performed by Chi square test and Fisher's test for univariate analysis, then logistic regression with backwards elimination method for multivariate analysis. Results. For 6,725 patients undergoing initial lumpectomy for cancer, 328 surgeons reported 1,451 (21.6 %) patients had one or more re-excisions. The most common reasons for re-excision were ink positive margins in 783 (49.7 %), margin <1 mm (34.3 %), and margin 1-2 mm (7.2 %). By multivariate analysis, re-excision rates were lower in patients aged less than 35 years, with White (non-) Hispanic ethnicity, and, among surgeons in solo practice, more years in practice and higher-volume practice. Conclusion. Half of re-excisions after initial lumpectomy were performed for margins that are positive. Most of the remainder were for negative close (<1-2 mm) margins. This information corroborates surgeon survey data regarding reasons for re-excision and provides proof of concept the Mastery(SM) Program can capture surgical outcome data in real time, providing opportunity and a method for future performance improvement.