The relationship between Helicobacter pylori and pancreatic cancer: a meta-analysis

BACKGROUND: The relationship between Helicobacter pylori (H. pylori, HP) infection and pancreatic cancer would be investigated in this article. METHODS: All cohort studies and case-control studies about H. pylori infection and pancreatic cancer up to October 2021 were searched in the databases of PubMed, Embase and Cochrane. The combined odds ratio (OR) and 95% confidence interval (CI) were calculated by R 4.1.0 software. Funnel plot and Egger test were used to evaluate publication bias. RESULTS: A total of 17 studies which included 8 case-control studies, 5 nested case-control studies, and 4 cohort studies were included in this study, and the results of this article have confirmed that the H. pylori infection was significantly correlated with the occurrence of pancreatic cancer (OR =1.30, 95% CI: 1.02–1.64), especially in economically underdeveloped areas (OR =2.10, 95% CI: 1.44–3.05). However, negative results were obtained in the relationship between CagA + H. pylori and pancreatic cancer. Similarly, we also did not find an association between vacuolating cytotoxin gene A-positive strains (VacA-positive H. pylori) and pancreatic cancer. The heterogeneity of this study was significant. Through a sensitivity analysis by the leave-one-out method, we found the results remained unchanged on the whole but the correlation between H. pylori infection and the occurrence of pancreatic cancer in the Asian population was significant. The tests for funnel plot asymmetry indicated that there might be obvious publication bias in this study. After carrying out the Egger test, we proved the existence of the publication bias in this study, which could have a certain impact on the results. DISCUSSION: Based on the currently available data, we confirm that H. pylori infection can increase the incidence of pancreatic cancer in general. CagA/VacA-positive H. pylori infection is not associated with the incidence of pancreatic cancer. H. pylori infection is significantly associated with the incidence of pancreatic cancer in economically underdeveloped areas, while the relationship between H. pylori infection and the incidence of pancreatic cancer in the Asian population is uncertain. In addition, more high-quality studies are needed to be included to confirm this conclusion.