Conservative mastectomies for breast cancer and risk-reducing surgery: the Memorial Sloan Kettering Cancer Center experience.

Demand for conservative mastectomies continues to increase as more patients choose to undergo breast reconstruction, often with simultaneous contralateral prophylactic mastectomy (CPM). In addition, the increasing use of risk-reducing surgery in high-risk groups has contributed to the increased use of these techniques. We have reviewed the indications and outcomes of a large group of patients undergoing nipple-sparing mastectomy (NSM) at this institution. In total, 728 nipple-sparing mastectomies (NSMs) were performed in 413 patients between 2000 and 2013, for treatment of breast cancer (n=269) or risk reduction (n=459). Of 728 NSMs performed, 177 (24.3%) were in patients known to have a BRCA1 or BRCA2 germline mutation, or a genetic variant of uncertain significance. There was an incidental finding of ductal carcinoma in situ (DCIS) or invasive carcinoma in 22 (4.8%) and 8 (1.7%) of 459 prophylactic NSMs, respectively. In addition, unexpected invasive carcinoma was found in 17 of 98 therapeutic NSMs (17.3%) performed for DCIS. At median follow-up of 49 months, there were no known cases of local recurrence and only one case of regional recurrence. Immediate breast reconstruction was performed in 409 patients, most of whom underwent tissue expander/implant based procedures (n=401). Although 273 breasts (37.5%) had some evidence of skin desquamation at follow-up, most resolved spontaneously with 47 breasts (6.5%) requiring debridement. Other complications included hematoma in seven breasts (1%) and wound infection in 31 breasts (4.3%). Expander/implant removal was required in 20 cases (2.8%). The nipple-areola complex (NAC) was subsequently excised in 10 of 728 breasts (1.4%) due to oncologic concerns following assessment of retroareolar tissue. NSM was successful in most patients with an acceptable complication rate and in few patients subsequently undergoing removal of the NAC. Patients requiring mastectomy for breast cancer or risk reduction may now benefit from conservative mastectomy techniques such as NSM, resulting in improved cosmesis and, possibly, a reduced psychological impact.