Background: Nipple-sparing mastectomy (NSM) is increasingly performed for invasive breast cancer. Growing evidence supporting the oncologic safety of NSM has led to its widespread use and broadened indications. In this study, we examine the indications, complications, and long-term outcomes of therapeutic NSM.
Methods: From 2003 to 2016, women undergoing NSM for invasive cancer or ductal carcinoma in situ (DCIS) were identified from a prospectively maintained database. Patient and disease characteristics were compared by procedure year, while complications were compared by procedure year using generalized mixed-effects models accounting for a random surgeon effect. Overall survival and time to recurrence were examined.
Results: Of the 467 therapeutic NSMs, 337 (72%) were invasive cancer, 126 (27%) were DCIS, and 4 (1%) were phyllodes tumors. Median age was 45 years (range 24-75) and median follow-up among survivors was 39.4 months. Three hundred and fifty-seven (76.4%) cases were performed in 2011 or after. When comparing NSMs performed before and after 2011, there was a significant increase in NSMs performed for invasive tumors (58% vs. 77%; p < 0.001). There was no difference in family history, genetic mutations, smoking status, neoadjuvant chemotherapy, prior radiation, nodal involvement, or tumor subtype. Twenty-one (4.5%) nipple excisions were performed, of which 14 were performed for cancer at the nipple margin. Forty-four breasts (9.4%) had complications that required re-operation. Fifteen patients had locoregional recurrence or distant metastasis.
Conclusions: NSM use for invasive carcinoma has doubled at our institution since 2011, while postoperative complications and recurrence rates remain low. Our experience supports the selective use of NSM in the malignant setting with careful patient selection.