# Prevalence of BRAF Mutation in Colorectal Cancer Among Lebanese Patients: A Descriptive Study

## TL;DR

This study finds that 5.3% of Lebanese colorectal cancer patients have a BRAF mutation, which is linked to tumor location and microsatellite instability.

## Contribution

The study provides the first data on BRAF mutation prevalence in Lebanese colorectal cancer patients.

## Key findings

- BRAF mutation was detected in 5.3% of the studied patients.
- BRAF mutation correlated with right-sided tumors and microsatellite instability.
- No significant association was found with age, gender, or metastases.

## Abstract

Background: Although the BRAF gene mutation in colorectal cancer has a prognostic value and a therapeutic interest, very few studies address the prevalence of this mutation in the Middle East, and hardly any among the Lebanese population. Moreover, we studied the correlation between this mutation and other clinical and pathological variables. Methods: In this descriptive, retrospective, single-center study, BRAF mutational status was reviewed in colorectal tumor samples collected from 2015 to 2021 of Lebanese patients with confirmed metastatic colorectal cancer. The genetic analysis was done in two different molecular laboratories. Clinical characteristics were selected from the computerized medical records of included patients. Statistical calculations were performed with SPSS (version 21.0) statistical software. Results: The study included 190 patients. BRAF mutation was detected in 10 patients (5.3%). A positive correlation was observed between the presence of a BRAF mutation and the right-sidedness of the tumor (p = 0.001) as well as with the presence of microsatellite instability (p = 0.004). However, we could not establish a relationship between BRAF mutation and other characteristics such as age (p = 0.682), gender (p = 0.392), the degree of histologic differentiation (p = 0.594), and the presence of peritoneal metastases (p = 0.707). Conclusions: The BRAF mutation was found in 5.3% of colorectal cancers in Lebanon. A positive correlation was suggested with the colon sidedness and the microsatellite instability. However, it was still insufficient to establish statistically significant associations between other variables and the BRAF mutation.