Correlation between Immunohistochemical Expression of Microfibril Associated Protein 5 and Hormone Receptors Status in Invasive Duct Carcinoma of Breast

Abstract

Background: Breast cancer (BC) represents a significant global health concern, with invasive ductal carcinoma/not otherwise specified (IDC/NST) comprising the majority of cases. In Egypt, BC stands as the leading cause of cancer-related mortality in women. Aim: This study aimed to investigate the role of Microfibril Associated Protein 5 (MFAP5) immunohistochemical expression in IDC/NST as a prognostic marker and a potential therapeutic target. Methodology: A retrospective cross-sectional study involving 106 IDC/NST samples was conducted, with each sample represented by a single tissue core in a tissue microarray setup. Diagnosis, grade, and subtype were confirmed via routine hematoxylin and eosin (H&E) staining, while hormone receptor profiles were reassessed through immunohistochemistry (IHC). Using a primary antibody against MFAP5, slides were prepared and evaluated for MFAP5 staining intensity. Results: The study revealed significant cytoplasmic MFAP5 expression in IDC/NST samples, particularly in high-grade tumors with elevated nuclear pleomorphism and Her2 overexpression. Furthermore, MFAP5 overexpression in primary tumor in situ components correlated with high mitotic counts, while stromal MFAP5 overexpression correlated with advanced stage and high tumor grades suggesting potential implications for anti-ER hormonal therapy responsiveness. Conclusion: Our findings underscore MFAP5 as a potential prognostic factor and a marker for hormonal therapy responsiveness in IDC/NST, warranting further investigation in primary lesions.