Epstein-Barr virus-associated gastric carcinoma among patients with pernicious anemia.

Approximately 9% of gastric carcinomas worldwide are associated with Epstein-Barr virus (EBV), making it the most frequent EBV-associated malignancy. Pernicious anemia, a condition with chronic gastritis and achlorhydria, is strongly associated with gastric carcinoma. Both chronic inflammation and the lack of stomach acid may influence the likelihood of EBV infection of the neoplastic gastric epithelium, but the prevalence of EBV-associated gastric carcinoma among patients with pernicious anemia is unknown. Therefore, we conducted a Danish nationwide case-control study comparing gastric carcinoma patients with pernicious anemia (PA-GC) with those without pernicious anemia (nonPA-GC), frequency matched 1:2. Tumor tissues were reclassified by expert histopathologists blinded to pernicious anemia and EBV status. In total, 186 samples (55 PA-GC and 131 nonPA-GC) were identified. EBV-associated gastric carcinoma (EBV-GC) was more common among PA-GC compared with nonPA-GC, adjusted odds ratio (OR) = 2.53 (CI: 0.88; 7.14), p = 0.08, with further adjustment for lymphocytic infiltrate OR = 2.94 (0.99-8.67), p = 0.05. Gastric carcinomas with signet-ring cell morphology were significantly less common in patients with PA-GC compared with nonPA-GC (OR = 0.05, CI 0.01; 0.24). Although these conditions are rare, we found suggestive evidence that EBV-associated gastric carcinomas are more common among gastric carcinoma patients with pernicious anemia compared with those without.