Helicobacter pylori infection and the risk of colorectal cancer: a nationwide population-based cohort study.
BACKGROUND
The role of Helicobacter pylori (H. pylori) infection in the development of colorectal neoplasia has been a matter of scientific debate with controversial findings.


AIMS
This study examined the association between H. pylori infection and colorectal cancer (CRC) in a nationwide population-based Chinese cohort study.


METHODS
A total of approximately 3,936 individuals with newly diagnosed H. pylori infection (the H. pylori-infected cohort) and 15,744 age- and sex-matched patients with diagnoses absence of H. pylori infection (the comparison cohort) from 2000 to 2005 were identified from Taiwan's National Health Insurance Research Database. The Kaplan-Meier method was used for measuring the cumulative incidence of CRC in each cohort. Cox proportional hazards models were used to compute hazards ratios (HRs) and accompanying 95% CIs for the estimation of the association between H. pylori infection and CRC.


RESULTS
The cumulative incidence of CRC was higher in H. pylori-infected cohort than that in the comparison cohort (log rank test, P < .001). After adjustment for potential confounders, H. pylori infection was associated with a significantly increased risk of CRC (adjusted HR = 1.87, 95% CI = 1.37-2.57). In addition, the HR of CRC appeared to increase with increasing frequency of clinical visits for H. pylori infection.


CONCLUSIONS
Our study demonstrated that H. pylori infection was associated with an increased risk of CRC, which warrants confirmation and exploration of the underlying biologic mechanisms by future studies.