Prognostic significance of membrane-associated mucins 1 and 4 in gastric adenocarcinoma.

Aberrant expression of mucins is likely associated with cancer biology as alterations in the expression and/or glycosylation patterns of various mucins have been noted. Expression of the mucin family in gastric cancers has been reported in numerous studies, but the results are conflicting. Therefore, we investigated the potential use of mucin (MUC)1 and 4 as prognostic markers in gastric cancer according to histological subtype. Three-hundred and sixty-five gastric adenocarcinoma patients who underwent surgical resection were selected for this study. Among the 365 gastric cancer samples tested here, 34% consisted of early gastric cancer and 66% were advanced. In terms of location, 68.7% of the cohort had intestinal-type cancer and 30.7% had diffuse-type. We constructed tissue microarrays with formalin-fixed paraffin-embedded blocks of gastric cancer and these micro-arrays were evaluated for phenotypic expression of MUC1/4 using monoclonal antibodies. Two-hundred and ninety-two patients (92.7%) were positive for MUC1 and 216 (60.5%) were positive for MUC4. MUC1 expression was not correlated with any other clinicopathological variables such as age, gender, depth of invasion, lymph node metastasis, Lauren classification or recurrence. However, loss of MUC4 expression was significantly correlated with recurrence (p=0.033). MUC4 expression was also significantly correlated with better disease-free survival (p=0.049) and particularly in the intestinal-type (p=0.018). Our present findings demonstrated that loss of MUC4 expression can be used as a prognostic marker in gastric cancer. Loss of MUC4 expression is a prognostic indicator of increased recurrence and poor disease-free survival in patients with gastric cancer.