Clinical Implications of Cancer Stem Cell Markers and ABC Transporters as a Predictor of Prognosis in Colorectal Cancer Patients

Background/Aim: Cancer stem cells (CSCs) and ABC transporters are associated with treatment resistance and outcomes of cancer patients. We aimed to investigate the prognostic implications of CSC markers and ABC transporters in colorectal cancer (CRC) patients. Materials and Methods: We collected 331 CRC samples and evaluated 3 CSC markers (SOX2, LGR5, and ALDH1) and 3 ABC transporters (ABCC2, ABCC3, and ABCG2) by immunohistochemistry. The association between the expression of these protein and patients' prognoses was statistically analyzed. Results: SOX2 was associated with longer overall survival (OS) (p<0.001). ABCG2 was associated with favorable overall survival (OS) p=0.001) and SOX2, and ABCC2 were associated with longer disease-free survival (DFS) (p=0.005 and 0.029, respectively). Multivariate analyses revealed that SOX2 was an independent prognostic factor for DFS [hazard ratio (HR)=2.701, p=0.044]. Conclusion: SOX2 and ABCC2 may be promising prognostic markers for CRC patients.