Prognostic and clinicopathological values of tissue expression of MFAP5 and ITM2A in triple-negative breast cancer: an immunohistochemical study

Introduction
Triple-negative breast cancer (TNBC) is a markedly aggressive molecular subtype of breast cancer; there is an urgent need to clarify the molecular mechanisms underlying the progression and metastases of BLBC, in order to find a novel targeted therapy. Microfibrillar-associated protein 5 (MFAP5) plays an essential role in the regulation of cell behaviour and survival. Integral membrane protein 2A (ITM2A) is a type II transmembrane protein, which is a member of a family of autophagy related proteins. The aim of this study was to assess the expression of MFAP5 and ITM2A proteins in tissues of BLBC using immunohistochemistry, in order to correlate the expression with clinicopathological and prognostic parameters of such aggressive cancer.

Material and methods
The present study included sections from archived paraffin blocks retrieved from 120 patients with TNBC. We collected cases from three years, i.e. from 2016 to 2019. We assessed expression of MFAP5 and ITM2A using immunohistochemistry.

Results
High expression of MFAP5 and low expression of ITM2A was associated with advanced stage (p = 0.007), higher grade of tumour (p = 0.005 and p = 0.004, respectively), the presence of lymph nodes metastases (p < 0.001 and p = 0.002, respectively), lower three-year RFS rate (p < 0.001 and p = 0.016, respectively), and lower three-year OS rate (p < 0.001).

Conclusions
MFAP5 and ITM2A are novel prognostic biomarkers for breast cancer and might be considered as promising therapeutic targets for patients with breast cancer, particularly TNBC molecular subtype, in the future.