Low rate of positive margins and re-excision after partial mastectomy in highly selected breast cancer patients: A Chinese single-institution experience

A recent randomized controlled trial firstly demonstrated that cavity shaving significantly decreased the rate of positive margins and re-excision among partial mastectomy (PM) patients. However, it remains unknown whether cavity shaving should be routinely applied to Chinese breast cancer patients undergoing PM. A total of 408 PM patients undergoing 410 PMs among 1796 surgically treated breast cancer patients at Fudan University Shanghai Cancer Centre from January 2015 to June 2015 were included in our study. Data were analysed with univariate or multivariate analysis. Overall, 11 of 410 cases (2.7%) had positive margins postoperatively. Moreover, only 24.6% of the cases (P<0.05) presented with ductal carcinoma in situ (DCIS), among whom 10.0% obtained positive margins. In multivariate logistic regression analysis, presence of mammographic calcifications was significantly associated with margin positivity (P<0.05, OR=6.06, 95% CI: 1.53-23.91). In conclusion, cavity shaving during PM should not be routinely performed in Chinese breast cancer patients, particularly in highly selected cases with a low prevalence of DCIS. PM patients with preoperative mammographic calcifications were more likely to have positive margins and might benefit more from cavity shaving.