Helicobacter pylori: Seroprevalence and colorectal cancer

Background: Previous studies have published controversial results regarding a connection between Helicobacter pylori infection and colorectal cancer. One possible mechanism is increased gastrin secretion in subjects infected with N. pylori, insofar as gastrin is known to be a trophic factor for the colonic mucosa. Objectives: To investigate a possible role of gastrin secretion in H. pylor i infection associated with colorectal cancer, and determine whether H. pyl ori infection is a factor in this disease. Methods: The serum gastrin levels and the presence of H. pyloyi IgG antibod ies were measured in 51 colorectal cancer patients and 51 control subjects. The cancer patients were also tested for carcinoembryonic antigen and CA 1 9-9. Results: H. pylori IgG antibodies were found in the serum of 41 (80.4%) of the cancer patients compared to 32 (62.7%) of the control subjects (P=0.05) . A significant correlation was found between CA 19-9 (r=0.3432, n=49, P=0. 01) acid seropositive H. pylori IgG antibodies in the serum of the cancer p atients (odds ratio 2.43, and 95% confidence limit 0.99-5.95), but none bet ween CEA and H. pylori IgG antibodies nor between the serum gastrin level a nd the presence of colorectal cancer. Conclusions: The results of this study indicate a significant association b etween seropositive H. pylori IgG antibodies and elevated CA 19-9 in colore ctal cancer patients, but no correlation between the serum gastrin level an d the presence of this cancer. H. pylori seropositivity is more prevalent i n patients with colorectal cancer.