Implications of New Lumpectomy Margin Guidelines for Breast-Conserving Surgery: Changes in Reexcision Rates and Predicted Rates of XXXX .

@entity1 @entity1137 @entity66 @entity41 @entity5 @entity513
BACKGROUND: The 2014 guidelines endorsed by Society of Surgical Oncology, the American Society of Breast Surgeons, and the American Society for Radiation Oncology advocate "no ink on @entity5 " as the new margin requirement for breast-conserving therapy (BCT). We used our lumpectomy margins database from 2004 to 2006 to predict the effect of these new guidelines on BCT. METHODS: @entity1 with neoadjuvant therapy, pure @entity513 -in situ, or incomplete margin data were excluded. We applied new ("no ink on @entity5 ") and old (>= 2  mm) margin guidelines and compared rates of positive margins, reexcision, and rates of @entity66 found at reexcision. RESULTS: A total of 437 lumpectomy surgeries met the eligibility criteria. Eighty-six percent had @entity513 , 12  % @entity1137 , and 2  % @entity513 and @entity1137 . Using a >= 2  mm margin standard, 36  % of lumpectomies had positive margins compared to 18  % using new guidelines (p  <  0.0001). Seventy-seven percent of @entity1 with "ink on @entity5 " had @entity66 found at reexcision. Fifty percent of subjects with margins <2  mm had @entity66 (p  =  0.0013) but would not have undergone reexcision under the new guidelines. With margins of >= 2  mm, @entity41 was seen in the shaved margins of 14  % of lumpectomies. @entity41 was more common in reexcisions for @entity513 -in situ <2  mm from a margin than for invasive @entity5 (53 vs. 40  %), although this was not statistically significant. CONCLUSIONS: Use of new lumpectomy margin guidelines would have reduced reoperation for BCT by half in our @entity1 cohort. However, @entity66 was present in many @entity1 who would not have been reexcised with the new guidelines. Long-term follow-up of local recurrence rates is needed to determine if this increase in @entity66 is clinically significant.
