Risk factors and p53 nuclear overexpression in early stage intestinal-type adenocarcinoma of the stomach.

In order to investigate the relationship between altered patterns of p53 expression and risk factors for stomach cancer, we have analyzed a group of 35 patients with early stage intestinal-type adenocarcinoma of the stomach. We assessed p53 nuclear overexpression by immunohistochemistry, using monoclonal antibody PAb 1801, and identified 15 out of 35 patients (43%) displaying nuclear overexpression of p53 protein. Significantly elevated odds ratios (O.R.) were observed for greater body mass index (highest quartile versus lowest quartile: O.R. = 7.9; 95% confidence interval (CI): 1.1 to 56.1) and younger age (< 60 vs. > or = 70 years: O.R. = 10; 95% CI, 1.43 to 50). The odds ratio for p53 overexpression in cigarette smokers was 2.8 (95% CI: 0.7 to 11.6) but not statistically significant. These data indicate that p53 mutations may be involved in the early stages of gastric carcinogenesis, especially in the development of intestinal-type adenocarcinoma.