TY - JOUR T1 - Matrix-producing Carcinoma as an Aggressive Triple-negative Breast Cancer: Clinicopathological Features and Response to Neoadjuvant Chemotherapy JF - Anticancer Research JO - Anticancer Res SP - 3863 LP - 3869 DO - 10.21873/anticanres.13536 VL - 39 IS - 7 AU - KAZUHIRO SHIMADA AU - TAKASHI ISHIKAWA AU - AKIMITSU YAMADA AU - SADATOSHI SUGAE AU - KAZUTAKA NARUI AU - DAISUKE SHIMIZU AU - TAKASHI CHISHIMA AU - ITARU ENDO Y1 - 2019/07/01 UR - http://ar.iiarjournals.org/content/39/7/3863.abstract N2 - Background: Breast matrix-producing carcinomas (MPCs) are rare, and usually triple-negative (TNBC; i.e. oestrogen receptor-, progesterone receptor-, and human epidermal growth factor receptor 2-negative). This study evaluated the clinical features, immunohistochemical profiles, and pathological response to neoadjuvant chemotherapy (NAC) of patients with MPCs. Patients and Methods: Five MPCs were identified among 247 patients with TNBC receiving anthracycline- and taxane-based NAC. Pathological response was assessed using surgical specimens. Results: All tumours were histological grade 3 according to pre-treatment core biopsies. Mean Ki-67 and p53 positivity were 65% and 90%, respectively. All tumours were TNBC, and epidermal growth factor receptor-, cytokeratin 5/6-, and vimentin-positive. Grade 3 (pathological complete response) was achieved in 0% (0/5) and 32% (77/242) of those with MPCs and with TNBCs of no specific histological type, respectively, and grade 1a (poor response) in 80% (4/5) and 13% (31/242), respectively. Conclusion: MPCs are basal-type TNBCs expressing epithelial–mesenchymal transition markers, with a poor response to standard NAC. Further studies are needed to improve the treatment of this rare but aggressive tumour. ER -