Abstract

Immunoreacivities for transforming growth factor-alpha(TGF-a) and epidermal grouwth factor receptor(RGFR) were assessed retrospectively in 81 cases of gastric adenocarcinomas to clarify the role of the autocrine mechanism in the cellular proliferation and progression of gas- tric cancer and to evaluate their value as the prognosticators of patients with gastric cancers. In addition to TGF-a and EGFR, also assessed in this study were such clinicopathologic features as differentiation, tumor size, gross apperance, serosal invasion, nodal status, distant metastasis and AJC(American loint Committee on Cancer) stage. Proliferative potential of the tumor was measured by calculating proliferating cell nuclear antigen labeling index(PCNA L. I.), the mean of which was 42.l +-l9.4(range, 6 to 85). The results were: 1) TGF-a and EGFR were overexpressed in 37(45.7%) and 35(43.2%) cases, respectively. 2) Concurrent overexpression of TGF-a and EGFR was found in 16(19.8%) cases. 3) There was no significant relationship between TGF-a, EGFR immunoreactivities and clinicopathologic feature. 4) Tumors belonging to high PCNA L.I. group(greater than or equal to 42.1) were significantly more for cases with synchronous overexpression of TGF-a and EGFR than cases with either TGF-a or EGFR overexpression and with normal expression of both.(p<0.05) 5) Neither TGF-a nor EGFR immunoreactivity was associated with 5 year survival rate. The above results show that the gastric cancer cells gain some advantage in proliferation via an autocrine loop between the TGF-a and EGFR. But, the potential role of autocrine mechanism in the progression of gastric cancer was not demonstrated in this study. TGFG-and EGFR were inadequate as prognosticators of patients with gastric cancers. Prospective randomized study is required to confirm these results.

• Keywords: TGF-a, EGFR, Gastric cancer