Prevalence of multiple infections and the risk of gastric adenocarcinoma development at earlier age

Abstract Helicobacter pylori and Epstein–Barr virus are well established infections for gastric cancer development. However, the role of cytomegalovirus alone or in combination with other infections is unclear. In this case-control study, the prevalence of different infections was evaluated, and their frequency was compared with clinicopathologic features among gastric cancer patients and normal volunteers from 2012 to 2017. Approximately two-thirds (61.9%) of the gastric cancer patients had at least 1 viral infection, while viral infection prevalence in normal volunteers was only 4.7% ( P = 0.021). The higher infection frequency in gastric cancer patients was observed for EBV (49.2%). No CMV DNA was detected in normal volunteers. In contrast, one-fourth of the gastric cancer patients were infected with CMV. Furthermore, CMV frequency in tumoral tissues (68.75%) was significantly higher than in nontumoral tissues (12.5%) ( P = 0.0311). Although H. pylori infection was significantly lower in tumoral tissues than in nontumoral tissues ( P = 0.0136), all tumoral tissues had cagA, while only 61.5% of nontumoral tissues were cagA positive. CMV-infected patients were affected 14 years earlier than uninfected, and CMV-negative patients (mean age = 56 vs. 69 and 70 years; P = 7.6×10 −3 and P = 2.7×10 −4 , respectively). Also, EBV viral load in earlier grades and stages was more than 100-fold higher than advanced grades and stages. Our results show a high level of infections in gastric cancer. The association of these infections especially with CMV contributes to gastric adenocarcinoma development at earlier age.