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.