Abstract P4-02-03: The diagnostic accuracy of breast MRI in the prediction of malignant invasion of nipple areolar complex (NAC) of breast
Authors: Lai H-W , Chen S-T , Chen D-R , Wu H-K , Kuo S-J 
Published: May 2016

Purpose: Nipple sparing mastectomy is increasingly used as a surgical treatment for breast cancer. To correctly predict the possibility of nipple invasion pre-operatively is critical important to prevent occult nipple invasion or early nipple recurrence. The objective of our study is to assess the diagnostic accuracy of breast MRI for the evaluation of malignant invasion of the nipple-areolar complex (NAC).

Material and Methods: From January 2011 to December 2013, patients with primary operable breast cancer diagnosed and treated at Changhua Christian Hospital (CCH), Taiwan were searched. The inclusion criteria were primary operable breast cancer patients, who received pre-operative breast MRI, and received breast cancer operation at CCH. The exclusion criteria were patients whose primary tumor was removed before definite cancer operation, those who received neoadjuvant chemotherapy, or patient's detailed data not available. Breast MRI examinations were retrospectively reviewed for nipple invasion or retraction, periareolar skin thickening, nipple areolar complex enhancement, relationship to the subareolar mass, malignant mass pattern, thickness of nipple-areolar complex enhancement, tumor-nipple distance and tumor size, and were correlated with pathologic findings. The accuracy of breast MRI to predict nipple invasion was compared with pre-operative image and post-operative pathologic reports.

Results: A total 704 primary operable breast cancers with pre-operative MRI and post operative pathologic reports were enrolled in our current study. In the total 704 patients, MRI showed signs of suspect NAC invasion in 160 (22.7%) patients. Total 41 (25.6%) patients were pathologic proven malignant invasion of NAC. In the final pathologic analysis, 57 pathologic confirmed NAC invasions were found in the 704 patients. The overall nipple invasion rate was 8.1% in this current study. The sensitivity of Breast MRI to predict NAC involvement was 71.9%. The Specificity of breast MRI to NAC invasion is 81.6%. The positive predictive value of breast MRI is 25.6%. The negative predictive value of breast MRI is 97.1%. The accuracy of breast MRI to predict NAC involvement is 80.8%. In univariate logistic regression analysis, tumor size, lymph node metastasis, central location of tumor, unilateral nipple enhancement, relationship to tumor, and HER-2 overexpression were prognostic factors for NAC invasion. In multivariate analysis, unilateral nipple enhancement (hazard ratio=4.944, CI: 1.938-12.616, P=0.001) was the most significant independently risk factor associated with the increased risk of NAC involvement.

Multivariate analysis of factors related to nipple invasion Multivariate analysisParametersOdds ratio95% CIpMRI tumor size0.8500.716-1.0090.063Distance to nipples (cm)1.1990.931-1.5440.160Location of tumor (Central)1.6830.724-3.9120.226Nipple enhancement (Unilateral)4.9441.938-12.6160.001Relationship (Yes)1.6160.625-4.1770.322MRI Lymph node metastasis (Yes)1.6740.870-3.2240.123

Conclusion: MRI is an useful diagnostic image method for the evaluation of malignant invasion of the nipple-areolar complex. Through preoperative breast MRI evaluation of NAC status, more personalized oncoplastic breast surgery could be performed.

Citation Format: Lai H-W, Chen S-T, Chen D-R, Wu H-K, Kuo S-J. The diagnostic accuracy of breast MRI in the prediction of malignant invasion of nipple areolar complex (NAC) of breast. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-02-03.