Classification of Local Recurrence After Nipple-Sparing Mastectomy Based on Location: The Features of Nipple–Areolar Recurrence Differ from Those of Other Local Recurrences

Background: Little information is available about the clinical and pathologic characteristics of local recurrence (LR) after nipple-sparing mastectomy according to the locations of LR. Methods: This study classified 99 patients into the following two groups according to the location of LR after nipple-sparing mastectomy: nipple–areolar recurrence (NAR) group and other locations of LR (oLR) group. The study evaluated whether the location of LR was associated with disease-free survival (DFS) after LR resection. Results: For about half of the patients (44.4 %) with NAR, the primary cancer was estrogen receptor (ER)-negative and human epidermal growth factor receptor 2 (HER2)-positive. Conversely, in most of the patients with oLR (79.2 %), the primary cancer was ER-positive and HER2-negative. Among the LR tumors, the frequency of noninvasive carcinoma in the NAR tumors was significantly higher than in the oLR tumors (51.9 % vs 4.2 %, respectively). During a median follow-up period of 46 months, the location of LR was not associated with DFS after LR. In the NAR group, the presence or absence of LR tumor invasiveness was the only factor associated with DFS. In the oLR group, age at primary surgery was the only factor associated with DFS. Conclusion: This multi-institutional retrospective study demonstrated that the features of NAR, such as the characteristics of the primary and recurrent tumors and the prognostic factors after LR resection, were quite different from those of oLR.