Background: 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 and methods: 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.
Results: The clinicopathological factors of tumor size ≧ 4 cm (p < 0.001), nipple-to-tumor distance (NTD) < 1 cm by mammography (p = 0.002), NTD < 1 cm 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).
Conclusion: 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.
Keywords: Breast cancer; Breast reconstruction; Nipple-sparing mastectomy; Nipple–areolar complex involvement; Sub-nipple biopsy.