Expression of immunohistochemical markers according to histological type in patients with early gastric cancer

Objective. We compared the biological characteristics of early gastric cancer (EGC) using immunohistochemical (IHC) staining among histological types. Materials and methods. IHC staining results were analyzed in 86 EGCs resected with endoscopic submucosal dissection to identify mucin phenotype and biological characteristics. Results. The histological type was classified as tubular adenocarcinoma (TAC), mixed adenocarcinoma (MAC), or poorly cohesive carcinoma (PCC). Significant differences in MUC-2 (34.4% vs. 10.7%, p < 0.05) and MUC-5AC (59.4% vs. 85.7%, p < 0.05) expression were observed between TAC and PCC. The poorly cohesive component of MAC showed stronger immunoreactivity to CD10 (46.2% vs. 14.3%, p < 0.05) but weaker reactivity to MUC-5AC (57.7% vs. 85.7%, p < 0.05), compared to that of PCC. E-cadherin and β-catenin expression levels significantly decreased in the poorly cohesive component of MAC (15.4% vs. 90.6%, p < 0.05; 7.7% vs. 90.6%, p < 0.05, respectively) and PCC (10.7% vs. 90.6%, p < 0.05; 14.3% vs. 90.6%, p < 0.05, respectively), compared to TAC. However, vascular endothelial growth factor expression significantly increased in the poorly cohesive component of MAC (42.3% vs. 9.4%, p < 0.05) and PCC (39.3% vs. 9.4%, p < 0.05), compared to TAC. Conclusion. IHC analysis showed that EGC histological types differ in terms of mucin phenotype and biological characteristics. The poorly cohesive components showed decreased E-cadherin and β-catenin expression levels and increased vascular endothelial growth factor expression. These characteristics may contribute to the poor prognosis of patients with MAC and PCC.