Helicobacter pylori Infection and Oesophageal Cancer Risk: Association Studies via Evidence-based Meta-analyses

Aims: Infection of Helicobacter pylori, a major cause of various gastric diseases, has been reported to play a role in the process of tumorigenesis and progression of gastric carcinoma. Some studies have been devoted to the relationship between H. pylori infection and oesophageal cancer and have yielded conflicting results. Whether infection of H. pylori is a risk factor for this cancer remains uncertain. In this study we aimed to evaluate the association of H. pylori infection with oesophageal cancer risk. Materials and methods: The associated literature was acquired through deliberate searching and selected based on the established inclusion criteria for publications, then the extracted data were further analysed by systematic meta-analyses. Results: In total, 195 articles were identified, of which 12 case-control studies concerning oesophageal cancer were selected. Oesophageal adenocarcinoma risk for H. pylori infection was 0.58-fold (95% confidence interval 0.48-0.70) (Z = 5.79, P < 0.01) compared with the controls. Oesophageal squamous cell carcinoma risk was 0.80-fold (95% confidence interval 0.45-1.43) (Z = 0.75, P > 0.05) compared with the controls. Compared with CagA-negative H. pylori, CagA-positive H. pylori markedly decreased oesophageal cancer risk. Conclusion: The pooled data suggest infection of H. pylori as a possible preventive factor for oesophageal adenocarcinoma and failed to suggest a significant association between H. pylori infection and oesophageal squamous cell carcinoma. Zhuo, X. et al. (2008). Clinical Oncology 20, 757-762 (c) 2008 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.