AN INVERSE RELATION BETWEEN CAGA(-PYLORI INFECTION AND RISK OF ESOPHAGEAL AND GASTRIC CARDIA ADENOCARCINOMA() STRAINS OF HELICOBACTER)

Gastric colonization with Helicobacter pylori, especially cagA(+) stra ins, is a risk factor for noncardia gastric adenocarcinoma, but its re lationship with gastric cardia adenocarcinoma is unclear. Although inc idence rates for noncardia gastric adenocarcinoma have declined steadi ly, paralleling a decline in H. pylori prevalence, rates for adenocarc inomas of esophagus and gastric cardia have sharply increased in indus trialized countries in recent decades. To clarify the role of H. pylor i infection in these tumors with divergent incidence trends, we analyz ed serum IgG antibodies to H. pylori and to a recombinant fragment of CagA by antigen-specific ELISA among 129 patients newly diagnosed with esophageal/gastric cardia adenocarcinoma, 67 patients with noncardia gastric adenocarcinoma, and 224 population controls, Cancer risks were estimated by odds ratios (OR) and 95% confidence intervals (CI) using logistic regression models. Infection with cagA(+) strains was not si gnificantly related to risk for noncardia gastric cancers (OR, 1.4; CI , 0.7-2.8) but was significantly associated with a reduced risk for es ophageal/cardia cancers (OR, 0.4; CI, 0.2-0.8), However, there was lit tle association with cagA(-) strains of H. pylori for either cancer si te (OR, 1.0 and 1.1, respectively). These findings suggest that the ef fects of H. pylori strains on tumor development vary by anatomical sit e. Further studies are needed to confirm these results and to assess w hether the decreasing prevalence of H. pylori, especially cagA(+) stra ins, may be associated with the rising incidence of esophageal/gastric cardia adenocarcinomas in industrialized countries.