Helicobacter pylori infection and markers of gastric cancer risk in Alaska Native persons: a retrospective case-control study

• Published in: Canadian journal of gastroenterology & hepatology Vol. 28; no. 6; pp. 305 - 310
• Main Authors: Keck, James William, Miernyk, Karen M, Bulkow, Lisa R, Kelly, Janet J, McMahon, Brian J, Sacco, Frank, Hennessy, Thomas W, Bruce, Michael G
• Format: Journal Article
• Language: English
• Published: Egypt Pulsus Group Inc 01.06.2014; Hindawi Limited
• Subjects: Adult; Alaska - epidemiology; Antigens, Bacterial - blood; Antigens, Bacterial - immunology; Bacterial Proteins - blood; Bacterial Proteins - immunology; Biomarkers, Tumor - blood; Blood Group Antigens; Female; Helicobacter Infections - blood; Helicobacter Infections - complications; Helicobacter pylori - immunology; Humans; Male; Middle Aged; Original; Pepsinogen A - blood; Population Groups - statistics & numerical data; Prevalence; Registries; Retrospective Studies; Risk Factors; Stomach Neoplasms - blood; Stomach Neoplasms - epidemiology; Stomach Neoplasms - etiology; Stomach Neoplasms - microbiology; Stomach Neoplasms - prevention & control; Alaska
• ISSN: 2291-2789; 2291-2797
• DOI: 10.1155/2014/892084

Alaska Native persons experience gastric cancer incidence and mortality rates that are three to four times higher than in the general United States population. To evaluate pepsinogen I, pepsinogen I/II ratio, anti-Helicobacter pylori and cytotoxin-associated gene A (CagA) antibody levels, and blood group for their associations with gastric cancer development in Alaska Native people. The present analysis was a retrospective case-control study that matched gastric cancers reported to the Alaska Native Tumor Registry from 1969 to 2008 to three controls on known demographic risk factors for H pylori infection, using sera from the Alaska Area Specimen Bank. Conditional logistic regression evaluated associations between serum markers and gastric cancer. A total of 122 gastric cancer cases were included, with sera predating cancer diagnosis (mean = 13 years) and 346 matched controls. One hundred twelve cases (91.8%) and 285 controls (82.4%) had evidence of previous or ongoing H pylori infection as measured by anti-H pylori antibody levels. Gastric cancer cases had a 2.63-fold increased odds of having positive anti-H pylori antibodies compared with their matched controls (P=0.01). In a multivariate model, noncardia gastric cancer (n=94) was associated with anti-H pylori antibodies (adjusted OR 3.92; P=0.004) and low pepsinogen I level (adjusted OR 6.04; P=0.04). No association between gastric cancer and blood group, anti-CagA antibodies or pepsinogen I/II ratio was found. Alaska Native people with gastric cancer had increased odds of previous H pylori infection. Low pepsinogen I level may function as a precancer marker for noncardia cancer.