Abstract
The expression of epidermal growth factor receptor (EGFR), which is coded by oncogene erb Bl, and transforming growth factor α (TGF-α) in human gastric cancer were compared with histological findings. The possibility that tumor cell growth is controlled by an autocrine mechanism was also investigated. EGFR was detected by staining frozen sections of gastric cancer by the immuno-histochemical method using anti-EGFR monoclonal antibody and TFG-α by similarly staining paraffin sections with anti-TGF-α polyclonal antibody. The results were compared with histopathological findings. EGFR was positive in 18 of 79 cases (22.8%): 17 of 49 cases of the differentiated type (34.7%) were positive, but only 1 of 30 cases of the undifferentiated type (3.3%). TGF-α was positive in 24 of 86 cases (27.9%): 6 of 48 cases of the differentiated type (12.5%) and 18 of 38 cases of the undifferentiated type (47.4%). Of 36 cases examined for both EGFR and TGF-α, both were positive in 3, all of which were advanced gastric cancer. These results suggest an association between the expression of EGFR and the degree of differentiation of gastric cancer cells. Therefore, it is possible that epidermal growth factor affects the proliferation of the differentiated type of gastric cancer cell. Of the tumor specimens expressing EGFR, some also produced TGF-α. This indicates that some human gastric cancer cells may control their own growth by an autocrine mechanism.
