Predictors of nipple-areolar complex involvement by breast carcinoma: histopathologic analysis of 787 consecutive therapeutic mastectomy specimens

Background Breast-conserving therapy (BCT) is an accepted therapeutic option for most breast cancer patients. However, mastectomy is still performed in 30–50% of patients undergoing surgeries. There is increasing interest in preservation of the nipple and/or areola in hopes of achieving improved cosmetic and functional outcomes; however, the oncologic safety of nipple–areolar complex (NAC) preservation is a major concern. We sought to identify the predictive factors for NAC involvement in breast cancer patients. Methods We analyzed the rates and types of NAC involvement by breast carcinoma, and its association with other clinicopathologic features of the tumors in 787 consecutive therapeutic mastectomies performed at our institution between 1997 and 2009. Results Among these, 75 cases (9.5%) demonstrated NAC involvement. Only 21 (28%) of 75 of cases with NAC involvement could be identified grossly by inspection of the surgical specimen (seven of these had been clinically identified). NAC involvement was most significantly associated with tumors located in all four quadrants (P 5 cm in size (P = 0.0014 for invasive carcinoma and P = 0.0032 for in-situ carcinoma), grade 3 tumors (P = 0.0192), tumors with higher nuclear grades (P = 0.0184), and tumors with HER2 overexpression (P = 0.0137). Conclusions On the basis of our findings, we have developed a mathematical model that is based on the extent and location of the tumor, HER2 expression, and nuclear grade that predicts the probability of NAC involvement by breast cancer. This model may aid in preoperative planning in selecting appropriate surgical procedures based on an individual patient’s relative risk of NAC involvement.