Ha-ras oncogene product in human gastric carcinoma: correlation with invasiveness, metastasis or prognosis.

c-Ha-ras oncogene product in human gastric carcinomas was examined by Western blotting and immunohistochemistry using anti-Ha-ras p21 antibody. In Western blotting, high levels of c-Ha-ras p21s were found in gastric carcinomas. Immunohistochemically, c-Ha-ras p21 was detected in 3 (11.1%) of 27 early carcinomas and in 63 (43.8%) of 144 advanced carcinomas. In advanced carcinomas, c-Ha-ras p21-immunoreactivity was correlated with the depth of tumor invasion and was stronger in metastatic tumors than in primary tumors. Patients with c-Ha-ras p21-positive carcinomas had a significantly worse prognosis than those with p21-negative carcinomas.