Cytoplasmic β‑catenin intensity predicts overall survival in rectal cancer but not colon cancer

Colorectal cancer (CRC) is a common malignancy with a rising global incidence. While genetic alterations such as mutations in APC, KRAS and TP53 are well‑established in CRC pathogenesis, the role of epithelial‑mesenchymal transition (EMT) and cell adhesion molecules in tumor progression has gained increasing attention. Among key regulators, p53 and β‑catenin serve critical roles in EMT and tumor behavior. In the present study, 171 patients with CRC who underwent curative resection between 2000 and 2007 were retrospectively analyzed. Immunohistochemistry was performed to evaluate p53 expression and β‑catenin localization (nuclear vs. cytoplasmic). β‑catenin staining intensity was classified as negative, weakly positive or strongly positive. Overall survival (OS) was assessed using Kaplan‑Meier analysis and the log‑rank test, and independent prognostic factors were identified using multivariate Cox proportional hazards regression analysis. Neither p53 expression nor nuclear β‑catenin intensity was significantly associated with OS in either colon or rectal cancer. By contrast, among patients with rectal cancer (n=103), those with lower cytoplasmic β‑catenin intensity exhibited significantly worse OS compared with those with higher intensity (median OS, 94 months vs. not reached; P=0.026). This association remained significant in multivariate analysis (hazard ratio, 2.27; 95% CI, 1.06‑4.85; P=0.034), independent of TNM stage and other covariates. These findings indicated that β‑catenin intensity may serve as a clinically relevant prognostic biomarker in rectal cancer, whereas p53 expression and nuclear β‑catenin intensity have limited prognostic value.