Nipple involvement in breast cancer: retrospective analysis of 2323 consecutive mastectomy specimens

Breast cancer surgical options now include nipple-sparing mastectomy (NSM), but there has been much controversy regarding the oncologic safety of the preserved nipple. This study evaluates frequency and patterns of occult nipple involvement in a large contemporary cohort of patients, aiming to improve patient selection for NSM. A total of 2323 consecutive mastectomy specimens with grossly unremarkable nipples were evaluated by sagittal sections through the entire nipple and subareolar tissue. Sixteen different clinical and tumor parameters were examined to predict cancerous nipple involvement. Nipple involvement was noted in 331 of 2323 (14.2%) mastectomy specimens. Occult nipple involvement rate was 10.7% (248 cases). Occult nipple involvement usually occurs as ductal carcinoma in situ. In univariate analysis, patient age, tumor size, tumor-to-nipple distance, tumor central location, tumor type, lymph node status, lymphatic vascular invasion, histologic grade, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (HER-2) amplification, and multicentric or multifocal tumor were associated with positive nipple involvement. By multivariate logistic regression analysis with the entire selection process, tumor size, tumor-to-nipple distance, central location, lymph node status, lymphatic vascular invasion, HER-2 amplification, and multicentric or multifocal tumor were shown to be associated with nipple involvement by carcinoma. Nearly 90% women undergoing mastectomy did not have occult nipple involvement. NSM may be a viable option in appropriate patient selection and setting. NAC preservation would be appropriate in HER-2 negative, axillary lymph node, and lymphatic vascular negative patients with small, solitary tumors located on the periphery of the breast.