Pernicious anemia (PA) is a risk factor for gastric cancer. Other autoimmune conditions may also contribute.
In a case-control study, we evaluated 47 autoimmune conditions among 35,499 gastric cancers and 200,000 cancer-free controls.
Six conditions were associated with increased gastric cancer risk (range of adjusted odds ratios [ORs]: 1.28-1.93, p<0.05): PA, membranous nephropathy, primary biliary cirrhosis, pure red cell aplasia, primary sclerosing cholangitis, and Graves' disease. PA was associated with 8 other autoimmune conditions (adjusted ORs: 1.57-4.54, p<0.05).
Autoimmune conditions associated with gastric cancer or PA may reflect effects of autoimmune gastritis or other carcinogenic pathways.