Helicobacter pylori, Atrophic Gastritis, and Breast Cancer Risk: A Prospective Cohort Study with 8-year follow-up

Helicobacter pylori (H. pylori), a known risk factor for gastric cancer, may have a role in the development of extragastric cancer; however, the evidence is equivocal. Using a prospective cohort, we investigated the relationship between H. pylori infection, atrophic gastritis (AG), and cancer risk. Incidence rates and hazard ratios (HR) derived by Cox proportional hazards models and adjusted for relevant confounders were assessed by H. pylori and AG status at baseline. The hospital-based study involved 1,252 participants, with an average follow-up time of 8 years. We identified 16 breast cancers, 14 lymphomas, four liver cancers, four cholangiocarcinoma, four skin cancers, and two gastric cancers. Both H. pylori and AG status increased breast cancer risk statistically significantly (HR = 7.35; 95% CI 2.08–27.13 and HR = 22.31; 95% CI 6.36–78.31). In a multivariable-adjusted model, we found a significant increase in risk among women with H. pylori infection and AG. (HR 6.46, 95% CI 1.61–26.02). H. pylori infection, AG, and a family history of breast or gastric cancer were independent risk factors for breast cancer. In conclusion, women who have H. pylori infection and AG are more likely to develop breast cancer, and screening programs should focus on identifying these individuals.