Achieving Tumor Free Margins: Intraoperative Pathology Consultation to Lower Re-Excision Rates at a Community Hospital

Objective: Achieving tumor free margins in a single surgery is the primary goal for breast conserving therapy (BCT). It is not uncommon for these patients to undergo more than one operation for positive margins. Within our patient population, lumpectomies requiring re-excision had gross pathological findings that could have warranted further margin excision at the index surgery.

Material and Methods: 579 patients who underwent lumpectomy were reviewed retrospectively from 2010 to 2017. 478 cases of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) were included. 91 patients underwent re-excision. Gross specimen findings that came within 2mm margins for DCIS and ink-on-tumor for IDC were considered potentially avoidable re-excisions based on the Society of Surgical Oncology-American Society for Radiation Oncology Consensus Guideline on margins. 35 cases of 91 re-excisions were found to have positive margins on gross pathologic evaluation.

Results and conclusion: The re-excision rate from 2010 to 2017 was calculated to be 19% with an average of 11 women each year. 38% of these patients had grossly positive margins. The re-excision rate according to types of histopathology was 28% for DCIS, 55% for IDC, and 53% for combined DCIS-IDC. The re-excision rate for BCT is 25% in the US. Re-excision surgery has the potential for added discomfort, surgical complications, increased health care cost, and additional emotional stress for patients. Our re-excision rate could have been reduced from 19% to 12%, by over one-third, if intra-operative pathology consultation had been utilized, with the highest impact in patients with IDC and combined DCIS-IDC.

Keywords: Re-excision; Lumpectomy; Breast conserving therapy; Ductal carcinoma in situ; Invasive ductal carcinoma