# Mismatch Repair System Gene Expression in FFPE Samples from Breast Cancer Patients

## TL;DR

This study examines the expression of mismatch repair genes in breast cancer samples to understand their role in tumorigenesis.

## Contribution

The study provides new data on hMSH2 and hMSH6 gene expression in formalin-fixed paraffin-embedded breast cancer samples.

## Key findings

- Only 11.23% of samples expressed hMSH2 and 4.5% expressed hMSH6.
- No associations were found between gene expression and tumor staging or hormone receptor status.

## Abstract

Background/Objectives: Cancer characteristics are mainly due to mutations in genes that regulate key pathways. One mechanism for identifying and correcting these mutations is the Mismatch Repair System. Given the lack of data on MMR in breast cancer FFPE samples, this study aims to examine hMSH2 and hMSH6 gene expression in FFPE tumor biopsies. Methods: One hundred patients with breast cancer were included in this study, from which tumor samples were obtained. Expression of the hMSH2 and hMSH6 genes was evaluated by qPCR. Results: Out of 100 tumor samples, 89 were suitable for molecular analysis. Of these, 10 (11.23%) expressed the hMSH2 gene and 4 (4.5%) expressed the hMSH6 gene. No associations were found between hMSH2 and hMSH6 expression and tumor staging, HER2, ER, PR, or Ki-67 expression. Conclusions: Our results suggest that the expression of the proposed markers is decreased in breast tumorigenesis.