Role of MUC1 and MUC5AC expressions as prognostic indicators in gastric carcinomas.

BACKGROUND AND OBJECTIVES

The aim of this study is to clarify the relationship between the expression of MUC1 and MUC5AC mucins and the clinicopathological features in human gastric carcinomas using the mouse monoclonal antibodies VU-4H5 and Clone 45M1, respectively. Furthermore, the possibility of using phenotypes (MUC1+/MUC5AC+, MUC1+/MUC5AC-, MUC1-/MUC5AC-, MUC1-/MUC5AC+) to predict prognosis of the patients is evaluated.

METHODS

Formalin-fixed, paraffin wax-embedded tissues from 76 cases of gastric cancer were examined for the expression of MUC1 and MUC5AC mucin antigens immunohistochemically using the avidin-biotin-peroxidase method.

RESULTS

Of the 76 cases, MUC1 and MUC5AC immunoreactivities were observed in 49 (64.5%) and in 32 (42.1%) of gastric carcinoma tissues, respectively. MUC1 expression was significantly correlated to the depth of invasion, lymph node metastasis, peritoneal dissemination, and tumor stage. On the other hand, MUC5AC was inversely associated with depth of invasion, lymph node metastasis, liver metastasis, and tumor stage. Multivariate analyses indicated that tumor stage and MUC1 mucin expression were independently correlated with overall survival. The patients with MUC1+/MUC5AC- antigen staining in carcinoma tissues showed the lowest survival rate among four phenotypes. In contrast, the patients with MUC1-/MUC5AC+ antigen staining in carcinoma tissues showed the highest survival rate.

CONCLUSIONS

Altogether these data suggest that combined evaluation of MUC1 and MUC5AC mucin staining may be clinically helpful to predict outcome in patients with gastric cancer.