Helicobacter pylori infection increases the risk of which condition the most?

• A. carcinoid tumor
• B. pancreatitis
• C. pernicious anemia
• D. gastric cancer

Answer: (D)

Chronic infection with Helicobacter pylori causes long-standing inflammation of the stomach lining, which over time leads to precancerous changes and an increased risk of gastric cancer. The bacteria trigger a sequence starting with chronic gastritis, then atrophic gastritis and intestinal metaplasia, followed by dysplasia and eventually intestinal-type gastric adenocarcinoma. This is the strongest, well-established cancer risk associated with H. pylori, and eradication of the infection can reduce but not always eliminate that risk.

Other options don’t have as clear or as strong a link. Pancreatitis isn’t a typical consequence of H. pylori infection. Pernicious anemia is related to autoimmune destruction of acid-secreting cells and intrinsic factor, not directly caused by H. pylori, though some associations exist. Carcinoid tumors can be related to certain types of gastritis or hypergastrinemia, but the most robust association with H. pylori among these choices is gastric cancer.