p53 accumulation is a prognostic factor in intestinal-type gastric carcinoma but not in the diffuse type

Background: The prognostic value of p53 nuclear accumulation in gastric can cer is still unclear, as shown by the discordant results still reported in the literature. In this study, we evaluated the correlation between p53 acc umulation and long-term survival of patients resected for intestinal and di ffuse-type gastric cancer. Methods: Eighty-three patients with carcinoma of the intestinal type and 53 patients with carcinoma of the diffuse type were included in the study. Im munohistochemical staining of the paraffin sections was performed by using monoclonal antibody DO1; cases were considered positive when nuclear immuno staining was observed in 10% or more of the tumor cells. Prognostic signifi cance of different variables was investigated by univariate and multivariat e analysis. Results: p53 positivity was found in 51.8% of intestinal-type and 50.9% of diffuse-type cases. No significant correlation between the rate of p53 over expression and age, sex, tumor location, tumor size, depth of invasion, lym ph node involvement, distant metastases, and surgical radicality was found in the two groups of patients. A statistically significant difference in su rvival rate was observed between p53-negative and p53-positive cases in the intestinal type (P < .05), confirmed by multivariate analysis (P < .005; r elative risk = 3.09). On the contrary, no correlation with survival was fou nd in diffuse-type cases according to p53 overexpression. Conclusions: These results suggest that the immunohistochemical detection o f p53 accumulation is a useful indicator of poor prognosis in the intestina l but not in the diffuse type of gastric cancer, and are indicative of dist inct molecular pathways and pattern of progression in the two histotypes.