Defining a place for nipple sparing mastectomy in modern breast care: an evidence based review

Breast cancer is a diverse disease that requires a fully integrated multidisciplinary approach. Breast surgery has undergone a revolutionary change leading us from the conventional radical mastectomy of the Halstedian era to the current motion of nipple sparing mastectomy (NSM). Despite the lack of randomized controlled trials, the technique of NSM continues to gain popularity as a prophylactic procedure in high risk patients. The current indications for NSM, if any, in the treatment of early invasive breast cancer remains uncertain and requires rigorous scientific scrutiny. This article aims to critically review the indications and limitations of NSM, discuss evidence based intra-operative protocols and to discuss ways in which radiation therapy may be incorporated in treatment planning following NSM. A comprehensive search of the scientific literature was carried out using PubMed to access all publications related to nipple sparing mastectomy. The search focused specifically on technique, current management, safety, and complications of these procedures. Keywords searched included "Nipple sparing mastectomy,""breast conserving surgery,""Nipple areola complex preservation" and "skin sparing mastectomy." NSM offers an opportunity to preserve native breast envelope without mutilation of nipple-areola complex (NAC), and avoids multiple surgical procedures required for reconstruction. NSM may be a reasonable alternative for prophylactic and select breast cancer patients without NAC involvement; however, oncological safety of NSM has not yet been fully demonstrated. Best available evidence suggests that patients should be selected based on study of breast duct anatomy by breast Magnetic Resonance Imaging, mammographic distance between tumor and nipple and obligatory intra-operative frozen section from retro-areolar tissue. Additional factors such as tumor size, axillary lymph node status, lymphovascular invasion and degree of intraductal component are also being used to either include or exclude NSM candidates based on institutional protocols. Heterogeneity of patients selected for NSM is great and the lack of standardization of preoperative investigations, intra-operative technique and pathologic sampling of retro-areola tissues mandates a multi-institutional prospective study to define and validate a role for NSM in invasive breast cancer and DCIS. Nipple necrosis or sloughing is an important problem after NSM which can be greatly reduced using alternative skin incisions. Even if the nipple survives, an insensate nipple and lack of sexual function is common and requires preoperative counseling and discussion. Finally the relation and timing of intra-operative versus adjuvant breast radiation and tailoring of dosage and delivery methods has not been fully explored. Although NSM reduces the psychological trauma associated with nipple loss, the oncologic safety as well as functional and aesthetic outcomes needs additional investigation.