Association between Helicobacter pylori infection and liver cancer mortality in 67 rural Chinese counties.

Background: Although a growing body of evidence from experimental and clinical studies suggests that Helicobacter pylori may play a role in liver cancer etiology, few epidemiologic studies have investigated this hypothesis.

Methods: Liver cancer mortality rates in 1986-1988 for the 67 Chinese counties were obtained from a nationwide survey among subjects aged 35-69 years. Blood samples were collected from selected individuals of the similar age range in the same 67 counties in 1989. H. pylori infection was evaluated by measuring its antibodies (IgG) in plasma samples using an enzyme-linked immunosorbent assay (ELISA). Pearson correlation and multiple regression analyses were performed to test our hypothesis.

Results: Prevalence rates of H. pylori infection were positively correlated with liver cancer mortality in both men (r = 0.43, p = 0.0002) and women (r = 0.41, p = 0.0005). This significant association persisted after adjustment for body mass index, income, cigarette smoking, alcohol consumption, HBsAg positivity, diabetes mortality, and salt-preserved vegetable intake. Stratified analysis revealed suggestive interactions of H. pylori prevalence with HBsAg positivity and urinary aflatoxin M1 in men in relation to liver cancer mortality.

Conclusion: The present study offers novel epidemiologic evidence suggesting that infection with H. pylori is associated with an increased risk of death from liver cancer among rural Chinese residents.