While Preservation of NAC is concerned to increase the risk of local recurrences in the retroareolar glandular tissue, nipple sparing mastectomy (NSM) is increasing in patients with breast cancer and has been shown to result in better cosmetic outcome and the benefit for quality-of-life. The purpose of this study is to identify the predictors of NAC involvement retrospectively and to develop a clinical predictive model to select the patients who can be offered preservation of NAC.
A total of 168 patients with primary operable breast cancer who received subcutaneous mastectomy for breast reconstruction at Saitama Medical Center during July 2013 to December 2017 were selected from the hospital’s surgical database.
Of the 20 patients who were resected NAC, NAC involvement positivity was only 50.0% (10/20). This revealed that NAC involvement with a sensitivity (SN) of 40.0%, a specificity (SP) of 93.0%, a positive predictive value (PPV) of 50.0% and a negative predictive value (NPV) of 89.9%. Correlation between NAC involvement and clinicopathological factors, tumor size ≧4cm (P < 0.001), DNT <1cm by MMG (P = 0.002), DNT <1cm by MRI (P < 0.001), nipple contrast findings by MRI (P < 0.001), tumor in central portion (P < 0.001), multicentirc/focal lesion (P < 0.001), c(N) positive (P = 0.014) were significant relation with NAC involvement. Each predictors were scored 0 or 1, and the total score of 0-3 points was defined as low risk, 4 points as intermediate risk, and 5-7 points as high risk. Depending on this categorized classification, the NAC involvement rate was 3.5% (5/142) in low risk, 68.7% (11/16) in intermediate risk, 90.0% (9/10) in high risk and there was a significant correlation between the risk group and NAC involvement (P < 0.001). Notably, assuming that NAC is preserved for low risk patients and is resected for intermediate and high risk patients, NACPI contributes to improve the accuracy of selecting the surgical procedures (SN 80.0%, SP 95.8%, PPV 76.9%, NPV 96.5%).
This study suggests that NACPI can help us indicating subcutaneous mastectomy for the breast cancer patients who request preserve NAC with more oncological safety.
Clinical trial identification
Legal entity responsible for the study
Saitama Medical Center.
Has not received any funding.
All authors have declared no conflicts of interest.