Risk of residual breast tissue after skin-sparing mastectomy.

Skin-sparing mastectomy (SSM) is an accepted surgical option for breast cancer treatment. SSM allows for preservation of the skin envelope and improved cosmesis. Despite initial concerns, large series have not revealed higher recurrence rates. There is, however, a paucity of data regarding the rates of residual breast tissue (RBT) left behind after SSM, what factors influence this, and the oncologic implications of RBT. Retrospective review identified 288 total mastectomies. Patients who had undergone SSM with excision of additional skin for reconstructive purposes, either at the initial oncologic surgery or at subsequent revision, were included in the final study group. Pathologic analysis was performed to evaluate excised skin. Data regarding demographics, tumor type, and treatment were collected. Comparison between patients who had pathologically confirmed RBT in the excised skin and those who did not was performed. Of 288 total mastectomies, 92 were SSM's, and 66 had skin specimens removed for nononcologic reasons, of these, 4 (6%) had RBT. Age at diagnosis (p = 0.806), BMI (p = 0.531), tumor size (p = 0.922), and estrogen receptor status (p > 0.999) did not contribute to increased RBT risk. At median follow-up of 33.5 months, there have been no recurrences. In addition, cost analysis reveals it is likely not cost-effective to perform pathologic evaluation of these specimens. SSM, performed at an academic medical center by fellowship-trained surgeons, has a very low rate of RBT, and does not compromise oncologic outcomes. Routine pathologic assessment of these skin specimens, removed for nononcologic reasons, may not be required.