Concordance and efficacy of intraoperative gross examination of margin vs final microscopic margin in breast conserving surgery: One year experience in a large metropolitan health care system
Shah A, Cole K, and Chitale DA. Concordance and efficacy of intraoperative gross examination of margin vs final microscopic margin in breast conserving surgery: One year experience in a large metropolitan health care system. Lab Invest 2018; 98:103-104.
Background: Controversy still exists regarding the optimal margin width in breast-conserving surgery (BCS) for breast cancer, but negative pathological margin status is an important component of optimal management. Margin reexcision is the most common indication for reoperation in patients undergoing BCS. Intraoperative margin evaluation (IOM) is generally an uncommon practice in BCS, but recently, our institutional surgeons required IOM status on most BCS specimens. Effective freezing and optimal sectioning for microscopic evaluation of fatty breast tissues is quite challenging due to technical limitations. Therefore, our aim was to assess concordance and efficacy of intraoperative gross examination of margin (IOGM) status with final microscopic margin. Design: Over 1 year period, all consecutive cases of BCS specimens where IOM status was requested by the surgeon were included in this study. For each case, a standard gross examination protocol was followed. Briefly, specimens were oriented, inked and serially sectioned at 3 mm thick slices. Gross observation of cut surfaces and a thorough palpation of each slice to identify firm tumor or biopsy cavity were carried out to assess closest margin distance. Margin status was reported with tumor / biopsy cavity distance to the closest margins as negative, close (< 1 mm) or positive. Positive and close margins prompted additional margin excision. Discordance with impact on clinical management was considered when IOGM was reported negative and microscopic final margin was either positive or close (<1 mm). Histological subtypes and other relevant clinicopathologic findings such as neoadjuvant status, primary vs recurrent tumor were recorded. Results: 176 women contributed to this study. There were 172/176 BCS, 2/176 mastectomies, 2/176 re-excisions. Primary diagnoses for all cases are listed in Table 1. The concordance between gross and final microscopic margin status is shown in Table 2. 13/176 (7.4%) cases had margins that were called negative on IOGM and turned out positive or close on microscopic final margin status (4 DCIS, 6 IDC-NOS, 1 IDC with lobular features, 1 IDC status post neoadjuvant chemotherapy, 1 ILC). (Table Presented) Conclusions: There was 93% concordance between IOGM negative status and microscopic specimen margins in this cohort. IOGM dramatically improved intraoperative TAT and reduced reoperation rates. Our study highlights a practical, efficient and easily adaptable method of IOM status evaluation.