Differential β-catenin expression levels are associated with morphological features and prognosis of colorectal cancer

beta-catenin, an epithelial-mesenchymal transition (EMT)-associated marker, is key in the progression of colorectal cancer (CRC). However, the prognostic significance of beta-catenin expression in patients with CRC remains controversial. In the present study, the expression of beta-catenin at the tumor invasive front and the tumor center was investigated, and the correlations amongst beta-catenin differential expression patterns and the clinicopathological characteristics and prognosis of CRC patients were determined. In total, 181 patients that were diagnosed with CRC (as determined by histopathological evaluation) and subjected to surgical resection at the First Hospital of China Medical University between 2000 and 2001 were examined, and CRC specimens were obtained. Immunohistochemical (IHC) staining of beta-catenin was performed for each specimen. The nuclear beta-catenin expression levels were identified to be significantly lower in the tumor center than at the tumor invasive front (immunoreactivity score, 0.05 +/- 0.303 versus 2.18 +/- 3.917; P<0.001). The presence of nuclear beta-catenin overexpression at the tumor invasive front was found to be correlated with the tumor, node, metastasis stage (P=0.020), lymph node metastasis (P=0.016) and histological differentiation (P=0.006). Survival analysis revealed that reduced membranous expression levels and increased nuclear expression levels of beta-catenin were statistically significantly associated with poor survival times. Furthermore, differential beta-catenin expression levels were associated with aggressive morphological features, EMT and a poor prognosis in CRC. Therefore, IHC analysis of beta-catenin is considered to be a useful marker to predict the prognosis in patients with CRC.