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.
Keywords: early gastric cancer; endoscopic submucosal dissection; histological type; immunohistochemistry.