Expression of epidermal growth factor receptor family proteins (EGFR, c-erbB-2 and c-erbB-3) in gastric cancer and chronic gastritis

The expression and coexpression of EGFR, c-erbB-2 and c-erbB-3 in 21 gastric cancers and 20 chronic gastritis was examined using immunohistochemistry on fresh frozen tissues considering clinicopathological variables. Generally, gastric cancer patients showed a higher incidence of EGFR, c-erbB-2 and c-erbB-3 overexpression than the group with chronic gastritis (81% and 43%; 38% and 45%; 35% and 20%,respectively), however statistically significant differences were found only for EGFR expression (p=0.01). No association between immunoreactivity of all growth factor receptors and the histopathological structure of gastric cancer was observed. EGFR and c-erbB-3 proteins were detected more frequently in patients with III/IV than in I/II of TNM stages, while c-erbB-2 overexpression was higher in I/II vs. III/IVstages. In chronic gastritis with intestinal metaplasia and or coexisting carcinoma lesions, a higher frequency of the expression of studied proteins was observed in comparison with chronic gastritis without those alternations; however,these differences were statistically insignificant. The percentage of positive cases with coexpression of two proteins was comparable in gastric cancer and chronic gastritis (33% and 35%) but the simultaneous expression of all three receptors was evident only in gastric cancer (19%). Our results indicate that at least one or two members of EGFR related receptors could appear in the early stages of gastric tumorigenesis. The enhancement of c-erbB-2 and c-erbB-3 reactivity seems to cooperate with EGFR activation in the gastric cancer development. Our results indicate the promotional rather than direct transformational role for EGFR supergene family; in gastric carcinogenesis.