Accuracy of intraoperative frozen-section analysis of breast cancer lumpectomy-bed margins

BACKGROUND: My colleagues and I have been using intraoperative frozen-section analysis (FSA) to evaluate lumpectomy margins in an attempt to reduce the number of additional operations that patients with ductal carcinoma in situ or stage I and II breast cancer would have to endure. We review our experience in breast-conservation therapy (BCT) at the University of Florida (Gainesville) to determine the effectiveness of this approach. STUDY DESIGN: Operative reports, operative logs, and pathology reports were retrospectively reviewed for patients who had BCT from January 2001 to January 2004. Ninety-seven patients (116 operations) were reviewed. RESULTS: Nineteen patients required an additional operation (19.6%). Forty-three patients had positive margins on paraffin-embedded histologic analysis (44.3%). Accuracy of FSA was 84% when evaluated on a per-case basis, and 96% on a per-slide basis. False negatives were identified in 22 patients, affecting the operative pathway of 19 patients (19.6%) and were identified more frequently in cases of ductal carcinoma in situ (p < 0.001). There were no false positives. Additional operative time required for FSA was approximately 13 minutes per case. Eighty-four (86.6%) patients had successful BCT and 13 patients (13.4%) required mastectomy. CONCLUSIONS: Intraoperative analysis of margins using FSA is effective at minimizing the number of additional operations, with 19 patients benefiting from immediate intervention in this study. The authors believe that the number of second operations prevented and the high BCT rates justify performing FSA. Ductal carcinoma in situ is more difficult to identify in FSA. Preoperative discussions with the patient should reflect these findings.