关键词: 乳腺肿瘤, 保乳术, 切缘, 再次手术, 影响因素分析

Abstract: Background　Breast-conserving surgery combined with whole breast radiotherapy has become the standard treatment for early breast cancer，but the most important disadvantage of breast-conserving surgery is that there may be tiny residual lesions at or close to the margin.Several studies have demonstrated that intraoperative frozen-section analysis（FSA） can assess the situation of margins，and prevent reoperation and reduce the local recurrence rate.Objective　To explore the factors influencing surgical margin positivity in FSA during breast-conserving surgery.Methods　According to the study criteria，we enrolled 629 patients undergoing FSA during breast-conserving surgery Tianjin Medical University Cancer Institute and Hospital from August 1，2014 and October 31，2016.We collected their clinical data，and analyzed the prevalence and associated factors of initial positive margin，the value of the distance from the mass to the nipple in the diagnosis of initial positive margin，and factors associated with the number of initial positive margins.Results　Among the 629 patients，434（69.0%） were found with initial negative margins，other 195 （31.0%） with initial positive margins.After extended resection，the margins of 92 （47.2%） patients became negative，but the margins of 7 （3.6%） patients were still positive.96 patients （49.2%） immediately underwent total mastectomy after being found with initial positive margins.526 patients （83.6%） had successful breast-conserving surgery.Those with initial positive margins and initial negative margins showed significant differences in terms of the distance from the mass to the nipple，tumor distribution along the duct，pathological type and lymph node metastasis prevalence （P<0.05）．Multivariate logistic regression analysis showed that the distance from the mass to the nipple〔OR=0.830，95%CI （0.700，0.982），P=0.030〕，and tumor distribution along the duct〔OR=0.232，95%CI （0.103，0.521），P<0.001〕，pathological type 〔invasive carcinoma of no special type：OR=0.268，95% CI （0.090，0.798），P=0.018〕，lymph node metastasis〔OR=0.154，95%CI （0.075，0.318），P<0.001〕 were the influencing factors of the initial positive margin in breast-conserving surgery．The ROC curve of the distance from the mass to the nipple for the diagnosis of initial positive margin was drawn，the area under the ROC curve was 0.572〔95%CI（0.520，0.624）〕，the optimal cut-off value was 4.55 cm，and the sensitivity was 0.815，the specificity was 0.333.The prevalence of 1，2，3 and 4 or more initial positive margins was 50.8%（99/195），28.2%（55/195），11.3%（22/195），and 9.7%（19/195），respectively.Menopause，and implementation of preoperative breast MRI were associated with less initial positive margins（P<0.05）．Conclusion　The distance from the mass to the nipple，tumor distribution along the duct，pathological type （mainly invasive carcinoma of no special type），and lymph node metastasis are the influencing factors of the initial positive margin in breast-conserving surgery.Non-menopausal patients and those receiving no preoperative breast MRI are more likely to be found with more initial positive margins.

Key words: Breast neoplasms, Breast-conserving surgery, Margin, Reoperation, Root cause analysis