Overexpression of nuclear β-catenin at invasive front in rectal carcinoma is associated with lymph node metastasis and poor prognosis

This study aims to investigate whether nuclear beta-catenin overexpression at invasive front in rectal carcinoma is associated with lymph node metastasis and prognosis. Immunohistochemistry was adopted to detect the expression of beta-catenin in rectal carcinoma and lymph node metastatic lesions. Spearman's rank correlation analysis and Tukey's test were used to evaluate the association between nuclear beta-catenin expression at invasive front in rectal carcinoma and lymph node metastasis. Kaplan-Meier method and multivariate Cox regression model were used to evaluate the prognostic value of nuclear beta-catenin overexpression at invasive front in rectal carcinoma for disease-free survival (DFS) and overall survival (OS). Overexpression of nuclear beta-catenin at the invasive front in rectal carcinoma in stage III-N-2 was significantly higher than that in stage III-N-1 (73.4 vs. 40.4 %, P < 0.001). Nuclear beta-catenin expression at the invasive front in rectal carcinoma was associated with the expression of nuclear beta-catenin in corresponding lymph node metastatic lesions (r = 0.297, P < 0.001). Overexpression of nuclear beta-catenin at the invasive front in rectal carcinoma was correlated with the number of metastatic lymph nodes (P < 0.001). Patients with nuclear beta-catenin overexpression at the invasive front in rectal carcinoma had poor DFS (P = 0.002) and OS (P = 0.003). Moreover, overexpression of nuclear beta-catenin at the invasive front was an independent prognosticator for unfavorable DFS and OS (P = 0.002 and 0.001). Our findings suggest that overexpression of nuclear beta-catenin at the invasive front in rectal carcinoma may be a useful marker to evaluate lymph node metastasis, as well as a promising predictor of poor prognosis.