Genetic Expression Pattern of Gastric Carcinomas According to Cellular Mucin Phenotypes

ABSTRACT

BACKGROUND: Gastric carcinomas (GCs) have recently been reclassified according to the mucin phenotypes. We aimed to characterize the relationship between the mucin phenotypes and the genetic alterations or the clinicopathologic parameters of GCs. METHODS: Immunohistochemistry was performed for MUC1, MUC5AC, MUC6, MUC2, CD10, p53, hMLH1, CerbB2 and E-cadherin in 150 GCs. The mucin phenotypes of the GCs were classified as 4 phenotypes gastric, intestinal, mixed and unclassified. RESULTS: MUC1, MUC5AC, MUC6, MUC2 and CD10 were expressed in 63.3%, 42.7%, 14.0%, 24.7% and 14.0% of the GCs, respectively. The mucin phenotypes of the GCs corresponded to the gastric type in 31.3%, the intestinal type in 20.0%, the mixed type in 15.3% and the unclassified type in 33.3%. The incidence of a p53 overexpression was higher in the gastric or mixed phenotype than in the intestinal or unclassified phenotype. MUC5AC expression, p53 overexpression and the gastric or mixed phenotype were associated with poor patient survival by multivariate analysis. CONCLUSION: This study suggests the gastric or mixed mucin phenotype may more likely go through the p53 pathway in carcinogenesis and the mucin phenotype may be considered as a prognostic indicator.