Helicobacter pylori infection and pancreatic cancer risk: A meta-analysis

OBJECTIVE: To assess whether the Helicobacter pylori (HP) infection can increase the risk of developing pancreatic cancer or not by meta-analysis. METHODS: Published studies about HP infection and pancreatic cancer risk were electronic searched in the databases of MEDLINE, PubMed, Web of Science, and CNKI. The correlation between HP infection and pancreatic cancer was demonstrated by odds ratio (OR) and corresponding 95% confidence interval (CI). The publication bias was assessed by Begg's funnel plot and Egger's linear regression test. RESULTS: We finally included eight case-control studies for this present meta-analysis with 1003 pancreatic cancer patients and 1754 healthy controls. One study performed in Austria, 3 from China, and 4 from the United States. For obvious statistical heterogeneity, the data were pooled by random effects model. The pooled data indicated that significant correlation between HP infection and pancreatic cancer was found with OR = 1.45 (95% CI = 1.09-1.92) under the random effects model. The results indicated that the HP infection can significantly increase the risk of developing pancreatic cancer. The publication bias was evaluated by Begg's funnel plot and Egger's linear regression test. The Begg's funnel plot was significant asymmetric at the bottom which indicated potential publication bias. The Egger's linear regression test also indicated significant publication bias (t = 3.21, P < 0.05). CONCLUSION: Based on present open published data, HP infection can significantly increase the risk of developing pancreatic cancer. However, for small number of studies included in this meta-analysis and publication bias, more case-control or cohort studies are needed to further confirm this conclusion.