Prognostic significance of UDP‐N‐acetyl‐α‐D‐galactosamine:polypeptide N‐acetylgalactosaminyltransferase‐3 (GalNAc‐T3) expression in patients with gastric carcinoma

Aberrant glycosylation occurs during development of gastric carcinomas. The initiation of mucin‐type O‐glycosylation is regulated by GalNAc‐T3 (UDP‐N‐acetylgalactosamine:polypeptide N‐acetyl‐galactosaminyltransferase‐3). However, the clinical significance of GalNAc‐T3 expression in human gastric carcinoma has not yet been demonstrated. In the present study, we investigated the relationship between immunohistochemical GalNAc‐T3 expression and various clinicopathologic factors, including prognosis, in 117 gastric carcinoma patients. Of 117 gastric carcinomas examined, 59 (50.4%) showed strong expression of GalNAc‐T3. Strong expression was detected in 38 of 59 (64.4%) differentiated type and in 21 of 58 (36.2%) undifferentiated gastric carcinomas, indicating that the expression of GalNAc‐T3 correlated significantly with tumor differentiation (P=0.0023, x2 test). Overall 5‐year survival rate in patients with strong GalNAc‐T3 expression (71.0%) was significantly better than that of patients with weak expression (49.3%) (P=0.0197, log‐rank test). Multivariate analysis identified GalNAc‐T3 expression as an independent prognostic factor (P=0.0158, Cox proportional hazards model). Our data suggest that GalNAc‐T3 expression may be a useful marker for prognosis and differentiation of gastric carcinomas. (Cancer Sci 2003; 94: 32–36)