AIM: To investigate the changing pattern of β-catenin expression and its prognostic value in advanced colorectal cancer (CRC). METHODS: Archival tumor samples were analyzed for β-catenin using immunohistochemistry (IHC) in 95 patients with advanced CRC. RESULTS: Membranous β-catenin expression was found in the normal colorectal epithelium. Almost 100% of CRC cases showed membranous and cytoplasmic expression,and 55 (58%) cases showed nuclear expression. In univariate (Kaplan-Meier) survival analysis,only the nuclear index (NI) was a signifi cant predictor of disease-free survival (DFS) (P = 0.023; n = 35),with a NI above the median associated with longer DFS (34.2 mo) than those with a NI below the median (15.5 mo) (P = 0.045,ANOVA). The other indices were not significant predictors of DFS,and none of the three tested indices (for membranous,cytoplasmic,or nuclear expression) predicted disease-specific survival (DSS). However,when dichotomized as positive or negative nuclear expression,the former was a signifi cant predictor of more favorable DFS (P = 0.041) and DSS (P = 0.046). CONCLUSION: Nuclear β-catenin expression provides additional information in predicting patient outcome in advanced CRC. AIM: To investigate the changing pattern of β-catenin expression and its prognostic value in advanced colorectal cancer (CRC). METHODS: Archival tumor samples were analyzed for β-catenin using immunohistochemistry (IHC) in 95 patients with advanced CRC. RESULTS: Membranous β-catenin expression was found in the normal colorectal epithelium. Almost 100% of CRC cases showed membranous and cytoplasmic expression, and 55 (58%) cases showed nuclear expression. In univariate (Kaplan-Meier) survival analysis, only the nuclear index NI) was a signifi cant predictor of disease-free survival (DFS) (P = 0.023; n = 35) with a NI above the median associated with longer DFS (34.2 mo) than those with a NI below the median (15.5 mo (P = 0.045, ANOVA). The other indices were not significant predictors of DFS, and none of the three tested indices (for membranous, cytoplasmic, or nuclear expression) predicted disease-specific survival (DSS). However, when dichotomized as positive or negative nuclear express ion, the former was a signifi cant predictor of more favorable DFS (P = 0.041) and DSS (P = 0.046). CONCLUSION: Nuclear β-catenin expression provides additional information in predicting patient outcome in advanced CRC.