Low CDX2 expression and its prognostic significance in colorectal adenocarcinoma: prognostic insights from a cross-sectional study in Vietnam

Background CDX2, an intestine-specific transcription factor, is essential for colorectal epithelial differentiation and has been widely studied as a biomarker in colorectal adenocarcinoma (CRC). However, most previous studies applied a binary evaluation (positive/negative), which may underestimate its clinical significance. Methods We conducted a cross-sectional study of 356 surgically resected CRC cases at the University Medical Center, Ho Chi Minh City. CDX2 expression was evaluated by immunohistochemistry using an immunoreactivity score (IRS) that combined staining ratio and intensity. Associations between CDX2 expression and clinicopathological features were analyzed using chi-square and logistic regression tests. Results High CDX2 expression was observed in 88.8% of tumors, whereas 11.2% showed low expression. Low CDX2 was significantly associated with poor histological differentiation (OR = 3.79; 95% CI: 1.11–12.93; p = 0.033) and advanced local stage pT4a–pT4b compared with pT1–pT3 (OR = 2.86; 95% CI: 1.47–5.58; p = 0.002). No significant associations were found with patient age or sex. The combined scoring system allowed clearer discrimination between biologically distinct subgroups than the traditional binary method. Conclusions Low CDX2 expression is linked to aggressive pathological features and advanced tumor stage in CRC, highlighting its prognostic significance. Semi-quantitative evaluation of CDX2 using both staining ratio and intensity provides a more informative assessment that may aid risk stratification and guide clinical decision-making in CRC patients.