Braf mutation in colorectal carcinoma is associated with tumor depth, location, grade and pd-l1 expression: single center experience

Introduction: BRAF mutations in colorectal carcinoma (CRC) are a known marker of poor prognosis and aggressive tumor behavior. Aim: This study aimed to evaluate the correlation of BRAF mutations with tumor depth, anatomical location, histological grade, and programmed death-ligand 1 (PD-L1)
expression in colorectal carcinoma. Material and methods: A retrospective prospective analysis was conducted on 152
cases of CRC diagnosed at the Clinical Hospital Acibadem - Sistina. Tumor samples were tested for BRAF mutations and immunohistochemically stained for PD-L1 expression (clone
SP263). Tumor depth and location were documented, and histological grades were determined. PD-L1 expression was assessed at cut-offs of 1-10%, 10-50%, and 50-100% of positive tumor cells.Results: BRAF mutations were identified in 7.24% of cases, predominantly in right�sided colon tumors. Mutated cases exhibited greater tumor depth and higher histological grade (G3) compared to BRAF wild-type tumors. PD-L1 expression (50-100%) was significantly
associated with BRAF-mutated tumors, particularly in advanced stages (IIIC and IVA). These tumors showed a higher likelihood of being located in the right colon and were linked to poorer differentiation and increased immune checkpoint expression.Conclusion: BRAF mutations in CRC are associated with aggressive tumor characteristics, including greater depth, high grade, and right-sided location. The strong correlation with PD-L1 expression suggests potential therapeutic benefits of immune checkpoint inhibitors in BRAF-mutated CRC cases. Early identification of these mutations is crucial for optimizing patient outcomes.