Premium
Helicobacter pylori infection and gastric cancer: systematic review of the epidemiological studies
Author(s) -
John Danesh
Publication year - 1999
Publication title -
alimentary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.308
H-Index - 177
eISSN - 1365-2036
pISSN - 0269-2813
DOI - 10.1046/j.1365-2036.1999.00546.x
Subject(s) - medicine , helicobacter pylori , odds ratio , cancer , epidemiology , prospective cohort study , confounding , confidence interval , incidence (geometry) , observational study , cohort study , relative risk , gastroenterology , physics , optics
Background : The published epidemiological studies of chronic Helicobacter pylori infection and gastric cancer yield conflicting results, so there is uncertainty as to whether any material association exists and, if so, how strong it is. Aim : To review these studies quantitatively. Methods : A systematic review of sero‐epidemiological studies published before 1998 of H. pylori and gastric cancer, as identified by computer‐assisted literature searches of relevant journals, reference lists and discussions with authors. All relevant studies identified were included, subdivided by study design. The following was abstracted from published reports: adjusted odds ratio (or, in prospective studies, the risk ratio) and confidence interval, study design, type of controls, mean age, mean duration of follow‐up, assay methods, location of study, and degree of adjustment for confounders. Results : The 34 retrospective studies included in total 3300 gastric cancers, but their controls were of uncertain validity. The 10 ‘nested’ case–control comparisons in prospective studies included in total only 800 gastric cancers, and combined analysis of them yielded a risk ratio of 2.5 (95% CI: 1.9–3.4; 2 P < 0.00001) for gastric cancer in people seropositive for H. pylori antibodies. Conclusions : The prospective studies suggest that gastric cancer is 2 or 3 times as common in those chronically infected by H. pylori , but to help investigate causality, further observational studies are still needed, as are large‐scale randomized trials of whether antibacterial regimens reduce the eventual incidence of gastric cancer.