By how many times does Helicobacter pylori infection increase the risk of gastric cancer?

• A. 2-3 fold
• B. 8-10 fold
• C. No increased risk
• D. 4-6 fold

Answer: (D)

H. pylori infection promotes chronic gastritis that can progress to atrophic gastritis and intestinal metaplasia, setting the stage for gastric adenocarcinoma. When we look at large studies and meta-analyses, the inflammation-driven carcinogenic pathway typically yields a moderate-to-strong increase in risk, most commonly in the range of about 4 to 6 times higher for those with the infection. This magnitude is frequently cited in exams and guidelines as the representative increase for gastric cancer risk associated with H. pylori, though some populations or cancer subtypes may show lower (around 2–3) or higher estimates. The key point is that the infection raises risk substantially, and eradication of the organism tends to reduce that risk, supporting a causal relationship. An 8–10 fold increase is less consistent with the overall pooled data, and no increase would be incorrect.