Mucosal thickening adjacent to gastric malignancy: association with epidermal growth factor.

A high false negative rate from endoscopic forceps biopsy is well-known in gastric carcinoma. The initial aim of the present study was to determine whether possible thickening of adjacent nontumorous mucosa by nonspecific or specific trophic factors could contribute to this observation; 167 gastrectomy specimens (77 carcinomas, 14 lymphomas, 76 gastric ulcers) were examined and mucosal thickness measured. Mean thickness of uninvolved mucosa near carcinoma (1.4 +/- 0.08 mm, mean +/- SEM) and near lymphoma (1.5 +/- 0.1 mm) was in each case significantly greater than mucosal thickness near ulcer (1.14 +/- 0.05 mm) or at a distance in the same specimen (P less than 0.01 for each comparison). A subset of specimens representing 20% of carcinomas, showed marked mucosal thickening (2.01 +/- 0.05 mm) above the control mean. Immunohistochemical evaluation for intratumoral epidermal growth factor content (EGF) correlated with mucosal thickness in all groups examined (R = 0.67). Immunostaining for EGF receptor showed similar patterns of expression to those of EGF. EGF and EGF receptor contents were also correlated with depth of invasion when possible. In conclusion, the mucosal thickening adjacent to gastric malignancy may well contribute to the insensitivity of endoscopic forceps biopsy. More importantly, the higher tumor EGF and EGF-receptor contents seen in these lesions may prove to be a useful marker of biologic behavior and predictor of prognosis in these tumors.