ABSTRACT
PURPOSE: We have conducted this study to investigate the role of c-myc and AAT in gastric carcinoma progression and to see if clinical application of its expression in cancer tissue is of help for the diagnosis or in determining prognosis of gastric carcinoma. MATERIALS AND METHOD: The expression of c-Myc and AAT by immunohistochemical method applied to paraffin-embedded tissue sections of endoscopic biopsy materials of 71 cases of gastric carcinoma (24 early and 47 advanced) and immunoreactivities of antigens were correlated with histological differentiation of carcinoma, degree of tumor infiltration of mononuclear cells, serum levels of carcinoembryonic antigen (CEA) and presence of distant metastases. RESULTS: c-Myc in gastric carcinoma tissue was expressed in 24 cases (33.8%), and the rate of immunoreactivity of c-Myc was higher in the advanced carcinoma cases (38.2%) than early carcinoma cases (25.0%), but the difference was not stastistically significant. The elevated c-Myc expression correlated well with the elevation of serum CEA levels (P<0.05), with the presence of distant metastses (p<0.05), especially with peritoneal metastsis (p<0.05). AAT expression in gastric carcinoma was shown in 11 cases (14.1%), and the rate of immunoreactivity of AAT was significantly higher in advanced carcinoma cases (21.3%) than early carcinoma cases (4.2%) (p<0.05). The elevated expression of AAT correlated well with the elevation of serum CEA levels (p<0.05), and showed negative correlation with the degree of mononuclear cell infiltration in tumor area (p<0.05). The increased expression of c-Myc and AAT in gastric carcinoma correlated well (p=0.05, k= 0.31), which suggests the cooperative action of the two in gastric carcinoma progression. CONCLUSIONS: Our findings suggest that c-Myc expression may be a good marker of high grade malignancy in gastric carcinoma, and may be able to be used clinically in predicting distant metastases, especially for peritoneal dissemination. Our data also imply that c-myc, through its proliferative action, may play an important role in the progression of gastric carcinoma in cooperation with AAT which has immunosuppresive action.