Breast ductal carcinoma in situ with micro-invasion versus ductal carcinoma in situ: a comparative analysis of clinicopathological and mammographic findings

AIM: To determine the differences in clinicopathological and mammographic findings between ductal carcinoma in situ (DCIS) and ductal carcinoma in situ with micro-invasion (DCIS-MI) and explore clinicopathological and mammographic factors associated with DCIS-MI. MATERIALS AND METHODS: All DCIS patients with or without micro-invasion who underwent preoperative mammography at The Affiliated Hospital of Qingdao University from January 2016 through June 2020 were identified retrospectively. The correlations of clinicopathological findings with DCIS-MI were evaluated using univariate and multivariate binary logistic regression analyses. Imaging findings were compared between the groups by using the Pearson chi-square test. RESULTS: A total of 445 DCIS lesions and 151 DCIS-MI lesions were included in the final analysis. Large extent (>= 2.7 cm), high nuclear grade, comedo-type, negative progesterone receptor (PR), negative oestrogen receptor (ER), high Ki-67 and axillary lymph node metastasis were more frequently found in DCIS-MI than in DCIS (all p<0.05), and the first four of these were found to be independent predictors of DCIS-MI in the multivariate analysis (all p<0.05). Regarding imaging findings, compared to DCIS, DCIS-MI showed fewer occult lesions and more lesions with calcifications in mass, asymmetry, and architectural distortion (p=0.004). Grouped calcifications were usually associated with DCIS, while regional calcifications were commonly found in DCIS-MI (p<0.05). CONCLUSION: Large extent, high nuclear grade, comedo-type and negative PR were found to be independent predictors of DCIS-MI. Lesions with calcifications and regional calcifications were more likely associated with DCIS-MI on mammography. (C) 2021 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.