American Society of Breast Surgeons' Practice Patterns After Publication of the SSO-ASTRO-ASCO DCIS Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation.

ABSTRACT

BACKGROUND: The SSO-ASTRO-ASCO consensus guideline on margins for breast-conserving surgery with whole breast irradiation in ductal carcinoma in situ (DCIS) recommended a 2-mm margin. We sought to determine the impact of guideline publication on clinician practice. METHODS: A total of 3081 members of the American Society of Breast Surgeons (ASBrS) received a survey. Respondents' clinical practice type and duration, guideline familiarity, and margin width preferences before and after publication were assessed. Clinical practice pattern differences before and after publication were investigated using McNemar's test. RESULTS: A total of 767 (24.9%) of those surveyed responded. Most (92.4%) indicated guideline familiarity. Of those familiar, re-excision preference for DCIS and a positive margin remained the same before (94.4%) and after (94.3%) publication (McNemar's test p = 1.0). Following publication, surgeons were more likely to avoid re-excision to achieve margins wider than 2-mm (82.3% pre versus 87.5% post, p = 0.002). More surgeons performed re-excision for a close margin with pure DCIS (25.9% pre versus 36.5% post, p < 0.001) and with DCIS with microinvasion (DCIS-M) (40.7% pre versus 52.3% post, p < 0.001). For patients with invasive disease with extensive intraductal component (EIC) and a close margin, preference to avoid re-excision was similar (51.2% per versus 55.2% post, p = 0.071). CONCLUSION: Since guideline publication, surgeons are less likely to perform re-excision to obtain a margin greater than 2-mm and more likely to perform re-excision to obtain a 2-mm margin for both pure DCIS and DCIS-M. Preference to avoid re-excision with a close margin and EIC was similar before and after publication.