Differences in clinicopathological findings, cell kinetics and p53 expression between early gastric cancers with and without Helicobacter pylori infection.

Background/Aims: Helicobacter pylori (Hp) infection has been suggested to be a risk factor for gastric carcinogenesis. The aims of this study were to clarify differences in clinicopathological features, tumor cell kinetics and p53 expression between early gastric cancers developing within and at a distance from Hp actively infected mucosa and those away from the infected area. Methodology: A total of 91 consecutive patients who were diagnosed as having early gastric carcinoma were enrolled in this study. Phenol red solution and urea were sprayed over the surgically resected stomachs (the PR test). Tumors included in and away from positive (red color) areas on PR testing were considered as infected and non-infected cases, respectively, and compared for Ki67 (proliferative activity), ssDNA (apoptotic activity) and p53 immunoreactivity. Results: The average age of the infected cases (n=46) was 9 years younger than that for their non-inflected counterparts (n=45; P<0.0001). Depressed macroscopic and diffuse histologic types were more prevalent in the infected cases (P<0.05 and P<0.001, respectively). In neither intestinal nor diffuse histologic types were any significant differences in Ki67, ssDNA or p53 immunoreactivity apparent between the infected and non-infected cases. Conclusions: Cases of early gastric cancer developing within and at a distance from Hp inflected mucosa are clinicopathologically different although the presence of bacteria in the surrounding mucosa does not appear to affect tumor cell kinetics or p53 expression.