Predictors of Positive or Close Surgical Margins in Breast-Conserving Surgery for Patients with Breast Cancer

ABSTRACT

PURPOSE: This study aimed to determine the clinical and pathological factors associated with a higher rate of positive or close margins after breast-conserving surgery (BCS) by comparing these patients to patients with a negative margin. The second aim was to evaluate intraoperative resection margin status and reoperation rates for margin control in patients who underwent BCS. METHODS: We reviewed the clinical and pathological data of all women diagnosed with invasive breast carcinoma (IBC) and ductal carcinoma in situ (DCIS) at our institution between January 2006 and December 2016. RESULTS: During the 10-year study period, 785 patients were diagnosed with either IBC or DCIS, and 402 of these patients had undergone a total mastectomy as the primary treatment. The remaining 383 patients who underwent BCS were included in the final analysis. Of these, 100 patients (26.1%) had intraoperative positive or close margins. The remaining 283 patients (73.9%) had a negative margin intraoperatively, but 32 of these patients had positive or close margins on permanent sections. In the multivariate analyses, microcalcifications on mammograms (vs. none; odds ratio [OR], 1.911; 95% confidence interval [CI], 1.156−3.160), in situ carcinomas larger than 2.0 cm (vs. ≤2.0 cm; OR, 3.106; 95% CI, 1.193−8.086), and lumpectomy (vs. quadrantectomy; OR, 2.863; 95% CI, 1.268−6.622) showed a significant association with a positive or close surgical margins. Patients with intraoperative positive or close margins underwent more reoperation than those with negative margins (5.0% vs. 2.8%). CONCLUSION: After BCS, microcalcifications on mammograms, large-sized in situ carcinomas, and lumpectomy were more likely to have positive or close margins.