Several studies suggest an association between Helicobacter pylori infection and colorectal carcinoma or adenoma risk.
However, different authors report quite varying estimates.
Dr Natalia Zumkeller and team from Germany carried out a systematic review and meta-analysis of published studies.
The investigative team assessed the association between H pylori and colorectal carcinoma.
The team paid special attention to the possibility of publication bias and sources of heterogeneity between studies.
The investigators searched and cross-referenced an extensive literature to identify all published studies.
Summary estimates were obtained using random-effects models.
The presence of possible publication bias was assessed using different statistical approaches.
|The summary odds ratio for an increased colorectal cancer risk with H pylori was 1.4|
The investigators identified 11 human studies, published between 1991 and 2002.
A summary odds ratio of 1.4 was estimated for the association between H pylori infection and colorectal cancer risk.
The graphical funnel plot appeared asymmetrical, but the formal statistical evaluations did not provide strong evidence of publication bias.
The team observed that the proportion of variation of study results due to heterogeneity was small.
Dr Zumkeller's team concludes, “The results of this meta-analysis are consistent with a possible small increase in risk of colorectal cancer because of H pylori infection.
“However, the possibility of some publication bias cannot be ruled out, although it could not be statistically confirmed.”
“Larger, better designed and better controlled studies are needed to clarify the situation.”