Nipple-sparing mastectomy for early breast cancer: the importance of intraoperative evaluation of retroareolar margins and intra-nipple duct removal.

Abstract

Nipple-sparing mastectomy (NSM) is increasingly performed for breast cancer (BC) treatment. To ensure local control with this procedure, it is important to obtain clear surgical margins. Here, we aimed to estimate the confidence in intraoperative evaluation of the retroareolar margin (IERM) and the necessity of removing the intra-nipple ducts. In this retrospective cohort study, we evaluated 224 BC (infiltrating carcinoma 178, ductal carcinoma in situ 46) patients, who underwent NSM. IERM was determined via cytology and frozen sections. Following gland removal, the intra-nipple ducts were excised and embedded in paraffin for analysis. The retroareolar tissue was also paraffin-embedded and reanalyzed for definitive evaluation of retroareolar margins (DERM). The IERM predictive capacity in relation to DERM and the frequency of intra-nipple duct involvement were estimated. IERM classified the sub-nipple areolar complex area as cancer-free in 219 cases (97.8%). The condition of clear retroareolar margin was confirmed by DERM in 216 cases (98.6%). The IERM accuracy was estimated as 98.6%. Ductal carcinoma in situ was detected in intra-nipple ducts using paraffin sections in 1.8% of the cases, despite clear IERM (4/219). In conclusion, IERM affords high accuracy and its results are suitable to manage the nipple-areolar complex. Nevertheless, some patients may retain residual disease in the intra-nipple ducts; thus, these ducts should ideally be removed during NSM.