Reexcision Surgery for Breast Cancer: An Analysis of the American Society of Breast Surgeons (ASBrS) Mastery SM Database Following the SSO-ASTRO "No Ink on Tumor" Guidelines.

BACKGROUND: In February 2014 , the Society of Surgical Oncology and the American Society for Radiation Oncology released guidelines standardizing a negative margin after breast-conserving surgery (BCS) as "no ink on tumor" in patients with early-stage invasive cancer. We sought to determine whether reexcision rates after initial BCS decreased after guideline publication, using the ASBrS MasterySM of Breast Surgery Program.

METHODS: Between January 2013 and June 2015, data from the ASBrS MasterySM database was analyzed to determine reexcision rates pre and post guideline publication. Reasons for reexcision were evaluated as were the associations with patient and provider characteristics. Chi square test, Fisher's exact test, Student's t test, ANOVA, and multivariable logistic regression were used as appropriate. All analyses were performed using Microsoft Excel and SPSS, with p value <0.05 as significant.

RESULTS: Among 252 providers, the overall reexcision rate after initial BCS decreased by 3.7 % from 20.2 to 16.5 % (p < 0.001). Notable was a 13.8 % decrease (p < 0.001) in reexcisions being done for close margins. Of the analyzed physician and patient characteristics the majority of subgroups showed decreases between the two time periods; however, only "Percent Breast Surgery in Practice" was significant. On adjusted analysis, there were no specific patient factors associated with a reduction in reexcision rates.

CONCLUSIONS: Following the SSO-ASTRO "no ink on tumor" guideline publication, a reduction in overall reexcision rates and reexcision rates for close margins after initial BCS was observed in the ASBrS MasterySM database. More widespread implementation outside this group of early adopters is anticipated with ongoing dissemination.