SERUM ANTIBODIES AGAINST HELICOBACTER-PYLORI PROTEINS VACA AND CAGA ARE ASSOCIATED WITH INCREASED RISK FOR GASTRIC ADENOCARCINOMA

Infection with Helicobacter pylori is associated with the development of gastric cancer. To study whether the infection with H. pylori strai ns expressing the vacuolating cytotoxin (VacA) and/or the cytotoxin-as sociated protein (CagA) is associated with an increased risk of develo ping gastric adenocarcinoma, sera of 90 patients with gastric cancer a nd 90 matched controls with cardiovascular diseases were investigated for the presence of antibodies to VacA and CagA by immunoblot. Althoug h no significant difference in the overall H. pylori seropositivity wa s found between cancer patients and controls, antibodies against VacA or CagA were significantly more frequent in cancer patients than in co ntrol subjects. Seventy-five (97.4%) of 77 H. pylori-positive patients in the cancer group, but only 60 (84.5%) of 71 H. pylori-positive con trol patients had antibodies against either VacA or CagA (chi(2) = 6.6 3; relative risk, 2.00; 95% confidence interval, 1.18-3.39; P = 0.01). The presence of antibodies against VacA or CagA alone was also associ ated with an increased cancer risk (92.2% vs 80.3%; chi(2) = 5.30; rel ative risk, 1.74; 95% confidence interval, 1.08-2.78; P = 0.021, for V acA; and 87.0% vs 74.6%; chi(2) = 4.90; relative risk, 1.61; 95% confi dence interval, 1.06-2.45; P = 0.037, for CagA). The relative risk far gastric cancer was mainly elevated in patients under 65 years, but no t in patients at or over 65 years. There is evidence that infection wi th VacA- or CagA-producing H. pylori strains increases the risk of dev eloping gastric cancer, especially in younger patients.