Atypical Hyperplasia at the Margin of Frozen Sections from Breast-Conserving Surgery

Abstract

Purpose: Intraoperative frozen section analysis to assess margin status during breast-conserving surgery is often performed to reduce the rate of re-excision. Whether additional resection is required if atypical cells are found at the margin during breast-conserving surgery is controversial. The aim of this study was to evaluate the accuracy of intraoperative frozen section analysis and investigate the feasibility of additional resection in cases of atypical hyperplasia on frozen sections from breast-conserving surgery.Methods: A retrospective analysis was performed on 1,411 patients with invasive breast cancer who underwent breast-conserving surgery between July 2004 and June 2012. The microscopic margins of the intraoperative frozen sections and permanent sections were examined. Overall events (locoregional recurrence and distant metastasis) were analyzed between the negative margin group and the other margin group (including atypical hyperplasia, carcinoma in situ [CIS], and invasive carcinoma).Results: Of the 1,411 patients, 1,201 had negative margins and 210 had other margin types in the first frozen section. 68 patients had atypical hyperplasia on frozen section analysis. This atypical hyperplasia included atypical cells, atypical ductal hyperplasia, and atypical lobular hyperplasia. Of these 68 patients, the final findings on the permanent section were negative (n=32, 47.1%), atypical cells (n=16, 23.5%), and CIS (n=20, 29.4%). The rate of overall events and distant metastases were higher in the other margin group (9.5% vs. 5.4%, p=0.021) and (5.7% vs. 3.0%, p=0.045). Of the 1,411 patients, 44 (3.1%) had false-positive findings, and 15 (1.1%) had false-negative findings in the frozen sections, with an accuracy of 95.8%.Conclusion: The accuracy of intraoperative frozen section analysis was 95.8%, with 91.7% sensitivity and 96.4% specificity. Atypical hyperplasia on frozen section analysis requires additional resection at the time of breast-conserving surgery because of the possibility of CIS, but excessive resection may be performed in other cases. Therefore, sufficient consultation with patients is required.