Prognostic significance of combined expression of MUC1 and adhesion molecules in advanced gastric cancer.

The objective of the present study was to evaluate the combination of MUC1 and the status of adhesion molecules in advanced gastric cancers as a possible predictor of patient survival. Two hundred and two paraffin-embedded specimens of gastric carcinoma were examined by immunohistochemical staining using monoclonal antibodies against MUC1 mucin, E-cadherin and beta-catenin. The expression of MUC1 was considered positive if at least 10% of the neoplastic cells were stained. E-cadherin and beta-catenin were classified into four groups. Only a membranous pattern, which was stained as strongly as normal epithelial cells, was judged as normal. The absent pattern (loss of staining), cytoplasmic pattern (cytoplasmic staining with loss of membranous expression), and heterogeneous pattern (cytoplasmic staining with preservation of membranous expression) were considered abnormal. There was a significant relationship between MUC1-positive expression and abnormal expression of E-cadherin (P=0.017). The cancer with abnormal E-cadherin expression or MUC1-positive expression increased, indicating that the cancer invasion was deep. Survival analysis of the outcome revealed that the survival time for those with abnormal E-cadherin/MUC1-positive expression was shorter than for those with other expression patterns. Multivariate analysis revealed that patients with abnormal E-cadherin/MUC1-positive expression had a poorer prognosis with significance (P<0.0001). In conclusion, abnormal E-cadherin/MUC1-positive expression pattern in advanced gastric cancer is an independent unfavorable prognostic marker.