A. Botty Van Den Bruele1, B. Jasra1, C. Smotherman2, M. Crandall1, L. Samiian1 1University Of Florida College Of Medicine Jacksonville,Department Of Surgery,Jacksonville, FL, USA 2University Of Florida College Of Medicine Jacksonville,Center For Health Equity And Quality Research,Jacksonville, FL, USA
Introduction: A key factor in breast conservation therapy is obtaining negative surgical margins. Historical positive margin rates have been 20-40%, requiring re-excision to obtain clear margins. Recent ASTRO-SSO margin guidelines define a negative margin as no tumor at the inked margin for invasive cancer, and less than 2mm from the ink in DCIS. Discordance between the surgeon and the pathologist interpretation of specimen orientation has been reported to be as high as 31% and could influence the accuracy of re-excisions. This study examined whether the addition of surgeon performed intraoperative inking of the specimen would reduce re-excision rates after initial lumpectomy for breast cancer.
Methods: A retrospective review of a single institution prospective surgical database was performed from August 2009- May 2017 and included patients who had initial lumpectomy with pre-op diagnosis of invasive breast carcinoma or DCIS. Intraoperative specimen inking of all initial lumpectomy specimens was performed by the surgeons after Nov 2015. Re-excision rates after initial lumpectomy was compared across three time periods: before margin guideline publication (Jan 2014) vs. after guideline adoption (Jan 2014 – Oct 2015), vs. after the addition of surgeon performed intraoperative specimen ink (Nov 2015- May 2017).
Results: A total of 400 initial lumpectomies for DCIS and invasive carcinoma were evaluated. Overall re-excision rate was 21% (n=84). There was no difference in overall re-excision rate across the 3 time periods. Patient with DCIS were 2.8 times more likely to undergo re-excision for margins as compared to patients with invasive carcinoma (p<.0001) and this difference persisted across all time periods. There was a consistent reduction in re-excision for invasive cancer with adoption of new guidelines and addtion of IOP specimen ink.
Conclusion: Re-excision rates after initial lumpectomy remain significantly higher for DCIS than for invasive disease. Although margin guidelines improved re-excision rates, the addition of surgeon performed intraoperative inking of the lumpectomy specimen provided added reduction in re-excision of invasive carcinoma, but not in DCIS. Better understanding of biology of DCIS may improve local therapy for this entity.
