Prognostic Significance of ARID1A, PTEN and PD-L1 Expressions and MMR Status in Colorectal Cancer Tissue

Objective: Studies on the clinical significance and frequency of adenine-thymine-rich interactive domaincontaining protein 1A (ARID1A) mutation or protein expression and the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) protein expression in colorectal cancer (CRC) are conflicting.In this study, we investigated the relationships between ARID1A and PTEN expression, programmed death ligand 1 (PD-L1) expression, mismatch repair (MMR) status, and prognosis in patients with metastatic CRC. Material and Methods:Archival CRC formalin-fixed paraffin-embedded tissues were evaluated.The protein expression levels of ARID1A, PTEN and PD-L1 were investigated using immunohistochemistry (IHC).The MMR proteins were determined by the IHC analysis.The associations between clinical and pathological parameters and survival were investigated. Results:The median duration of follow-up was 43.4 months [95% confidence interval (CI), 39.7-47.15)].The median overall survival (OS) was 33 months (95% CI, 25.8-40.2),and the median progression-free survival was 17.25 months (95% CI, 11-23.4).The microsatellite stable status, human epidermal growth factor receptor type 2 positivity, and strong ARID1A expression were found to be significantly associated with poor survival, but no significant relationship was found between PD-L1 or PTEN expression and survival. Conclusion:Comprehensive studies on the molecular basis of the role and significance of ARID1A mutations and expression in mCRC may provide valuable information.The limited number of patients included in this study and the variations in the evaluation and interpretation of the studied biomarker parameters are factors that may hinder the precision of the results obtained.