Mucin Expression in Gastric Cancer: Reappraisal of Its Clinicopathologic and Prognostic Significance

Abstract

Context.—The clinical validity of mucin expression in gastric cancer is debated. Whereas several reports demonstrate a correlation between mucin expression and prognosis, others deny such an association. Objectives.—This survival analysis study aims to elucidate the prognostic significance of mucin expression in gastric cancer. Design.—A retrospective survival analysis was done with 412 cases of gastric cancer characterized on the basis of MUC immunohistochemistry using MUC2, MUC5AC, MUC6, and CD10 antibodies; the cases were divided into those with a gastric, an intestinal, or a null mucin phenotype based on the predominant mucin. Results.—There was no association between mucin expression and survival when considering overall gastric cancers or the advanced gastric cancer subtype. However, early gastric cancers with a gastric mucin phenotype showed longer survival than those with an intestinal mucin phenotype (P = .01) or a null phenotype (P = .01). In particular, MUC5AC-positive early gastric cancers resulted in longer survival than did those that did not express MUC5AC (P = .009). The loss of MUC5AC expression was identified as an independent, poor prognostic factor in early gastric cancers using the Cox regression proportional hazard model (hazard ratio, 3.50; P = .045). Conclusions.—MUC5AC expression is significantly associated with patient survival and can be used to predict outcomes in the gastric cancers, especially in the early gastric cancers.