A novel nipple-areola complex involvement predictive index for indicating nipple-sparing mastectomy in breast cancer patients.

Abstract

Nipple-sparing mastectomy (NSM) is increasingly used in breast cancer patients, as it offers better cosmetic outcomes and improves quality of life. Nipple-areola complex (NAC) involvement must be accurately determined to identify which patients may be candidates for NSM. We aimed to identify the predictors of NAC involvement and develop a clinical predictive model to determine the patients for whom NAC preservation may be considered. Patients (n = 168) with primary operable breast cancer who underwent subcutaneous mastectomy for breast reconstruction at Saitama Medical Center from July 2013 to December 2017 were selected from the hospital's surgical database. The clinicopathological factors of tumor size ≧ 4cm (p < 0.001), nipple-to-tumor distance (NTD) < 1cm by mammography (p = 0.002), NTD < 1cm by magnetic-resonance imaging (MRI) (p < 0.001), nipple contrast findings by MRI (p < 0.001), tumor in central portion (p < 0.001), multicentric/focal lesion (p < 0.001), and clinical node involvement (p = 0.014) were significantly associated with the presence of NAC involvement. Each predictor was scored 0 or 1. A score of 0-3 points was defined as low risk, 4 points as intermediate risk, and 5-7 points as high risk. Using these classification criteria, NAC involvement rate was determined to be 3.5% in low-risk, 68.7% in intermediate-risk, and 90.0% in high-risk specimens. A significant correlation was observed between the risk group and NAC involvement (p < 0.001). This nipple-areola complex involvement predictive index can be used to determine the appropriate indication for NSM in breast cancer patients who request NAC preservation with more oncological safety.