Ha-ras oncogene product in human oral squamous cell carcinoma.

The expression of Ha-ras oncogene product (Ha-ras p21) in the biopsy or operation materials derived from 70 oral squamous cell carcinomas, 10 oral leukoplakias and 10 normal oral mucosae was examined immunohistochemically using anti-Ha-ras p21 antibody. Ha-ras p21 was detected in 43 (61%) of 70 carcinomas, 3 (30%) of 10 oral leukoplaskias and 3 (30%) of 10 normal oral mucosae. Patients with Ha-ras p21-positive carcinomas had a significantly worse prognosis than those with Ha-ras p21-negative carcinomas. These observations strongly suggest that the expression of Ha-ras p21 is a common event in oral squamous cell carcinomas, and that Ha-ras p21 serves as a tissue tumor marker for determining the prognosis of patients with oral squamous cell carcinomas.