H pylori is an important causative factor in gastric carcinogenesis.
However, its role in extragastric gastrointestinal malignancies, such as esophageal cancer, is controversial.
Dr Theodoros Rokkas and colleagues from Greece explored the relationship of H pylori infection, and H pylori cagA-positive strain with this malignancy by performing meta-analysis of all relevant studies.
|In adenocarcinoma patients there was an inverse relationship with H pylori prevalence|
|Clinical Gastroenterology and Hepatology|
The researchers performed extensive MEDLINE English language medical literature searches for human studies through 2007 with suitable keywords.
Pooled estimates were obtained by using fixed or random-effects model as appropriate.
The team evaluated heterogeneity between studies with the Cochran Q test, whereas the likelihood of publication bias was assessed by constructing funnel plots.
The researchers found that in adenocarcinoma patients there were inverse significant relationships with both the H pylori prevalence, and the prevalence of H pylori cagA-positive strain.
Similarly in patients with Barrett's esophagus, there were inverse significant relationships.
The research team noted that in patients with squamous cell carcinoma there were no significant relationships with both H pylori prevalence, and the prevalence of H pylori cagA-positive strains.
Dr Rokkas' team concluded, "The results showed an inverse statistically significant relationship of H pylori infection with both esophageal adenocarcinoma and Barrett's esophagus, which might suggest a protective role of the infection in these entities."
"On the contrary, no statistically significant relationship with squamous cell carcinoma was found."