OBJECTIVE: As conflicting studies have recently been published, we aimed to
determine if Helicobacter pylori (H. pylori) infection is associated with
gastric adenocarcinoma.
METHODS: This was a meta-analysis of observational epidemiological studies.
RESULTS: A total of 42 studies met the selection criteria and were categori
zed by the type of study design: eight cohort and 34 case-control studies.
The pooled odds ratio for H. pylori in relation to gastric carcinoma was 2.
04 (95% CI: 1.69-2.45). Both patient age (OR 0.77, 95% CI: 0.68-0.89) and i
ntestinal type cancers (OR 1.14, 95% CI: 1.05-1.25) were independent effect
modifiers. Analysis of other effect modifiers showed no relationship with
female gender (OR 0.76, 95% CI: 0.64-0.89), stage of cancer (advanced %) (O
R 1.12, 95% CI: 0.88-1.43), anatomical location (cardia %) (OR 1.54, 95% CI
: 0.32-7.39) or cohort (nested case-control) studies (OR 1.72, 95% CI: 0.32
-9.17). There was significant heterogeneity among the studies (tau(2) = 149
; p < 0.001). The quality of the studies varied considerably, with the majo
rity of excellent studies producing positive results and the very poor to m
oderate studies producing mixed results.
CONCLUSIONS: H. pylori infection is associated with a 2-fold increased risk
of developing gastric adenocarcinoma. (Am J Gastroenterol 1999;94:2373-237
9. (C) 1999 by Am. Cell. of Gastroenterology).