Epithelial Mesenchymal Transition and Immune Response in Metaplastic Breast Carcinoma

Abstract

Transició epitelial-mesenquimal; Carcinoma de mama metaplàstic

Transición epitelio-mesenquimatosa; Carcinoma de mama metaplasico

Epithelial-mesenchymal transition; Metaplastic breast carcinoma

Metaplastic breast carcinoma (MBC) is a heterogeneous group of infrequent triple negative (TN) invasive carcinomas with poor prognosis. MBCs have a different clinical behavior from other types of triple negative breast cancer (TNBC), being more resistant to standard chemotherapy. MBCs are an example of tumors with activation of epithelial–mesenchymal transition (EMT). The mechanisms involved in EMT could be responsible for the increase in the infiltrative and metastatic capacity of MBCs and resistance to treatments. In addition, a relationship between EMT and the immune response has been seen in these tumors. In this sense, MBC differ from other TN tumors showing a lower number of tumor-infiltrating lymphocytes (TILS) and a higher percentage of tumor cells expressing programmed death-ligand 1 (PD-L1). A better understanding of the relationship between the immune system and EMT could provide new therapeutic approaches in MBC.

This review was funded by grants from the Instituto de Salud Carlos III (ISCIII) (PI19/01331) and CIBERONC (CB16/12/00316 and CB16/12/00449), co-financed by the European Development Regional Fund. ‘A way to achieve Europe’ (FEDER), and by the Spanish Association Against Cancer Scientific Foundation (Grupos Coordinados Traslacionales aecc 2018).