Patients younger than 40 years with gastric carcinoma - Helicobacter pylori genotype and associated gastritis phenotype

BACKGROUND. In the general population, Helicobacter pylori (H. pylori, part icularly the cagA positive strain, has been associated with intestinal-type gastric carcinoma. Gastric carcinomas are rarely observed in patients age less than or equal to 40 years. Host-related factors have been thought to b e more important than environmental agents in these early-onset cancers. Th e aim of this study was to ascertain the possible role of H. pylori infecti on and that of cagA positive strains in the development of gastric carcinom a in these young patients. METHODS. In this case-control study, 105 gastric carcinoma patients (male-t o-female ratio = 1.1; mean age, 34.4 years; range, 16-40 years) and an equa l number of controls (matched for gender and age) were retrospectively sele cted from the same geographic area. The phenotypes of gastritis and H. pylo ri were histologically assessed, and the presence of the ureC gene, which i s indicative of H. pylori infection, and the cagA genotype were determined by polymerase chain reaction. Gastric carcinoma risk was calculated by both univariate and multivariate statistical methods, taking into account the c ancer phenotype, the gastritis phenotype detected in both patients and cont rols, and the H. pylori genotype. RESULTS. For 74 diffuse and 31 intestinal gastric carcinomas, multivariate logistic regression analysis produced results consistent with those of univ ariate statistical tests, showing a significant association between gastric carcinoma and both H. pylori infection (odds ratio [OR] = 2.79; 95% confid ence interval [CI] = 1.52-5.11) and cagA positive status (OR = 2.94; 95% CI = 1.56-5.52). CONCLUSIONS. In young Italian patients with gastric carcinoma, the signific ant association with cagA positive H. pylori infection suggests that the ba cterium has an etiologic role in both diffuse-type and intestinal-type gast ric carcinoma. Cancer 1999;85:2506-11. (C) 1999 American Cancer Society.