Hepatitis B virus and risk of non‐Hodgkin lymphoma: An updated meta‐analysis of 58 studies

Previous studies have focused on the relationship between hepatitis B virus (HBV) infection and non‐Hodgkin lymphoma (NHL). However, the results remain inconsistent and somehow conflicting in different subgroups. The aim of this study was to combine the findings of independent studies to comprehensively assess the association between HBV and NHL using a meta‐analysis. Relevant studies were identified through structured keyword searches in PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) database, and 58 studies with a total of 53 714 NHL cases and 1 778 591 controls were finally included. Pooled estimates indicated a significantly increased NHL risk in HBV‐infected individuals (summary odds ratio sOR]: 2.50; 95% confidence interval CI]: 2.20‐2.83) regardless of the study design (case–control studies: sOR: 2.47; 95% CI: 2.16‐2.82; cohort studies: sOR: 2.64; 95% CI: 1.78‐3.91). Considerable heterogeneity was observed across studies that was primarily attributed to the NHL subtypes (meta‐regression: P < .05). Overall, B‐cell NHL (sOR: 2.46; 95% CI: 1.97‐3.07) presented a stronger association with HBV infection than T‐cell NHL (sOR: 1.67; 95% CI: 1.34‐2.10). Within the B‐cell NHL subtypes, HBV infection was significantly associated with diffuse large B‐cell lymphoma (DLBCL, sOR: 2.06; 95% CI: 1.48‐2.88) and follicular lymphoma (FL, sOR: 1.54; 95% CI: 1.11‐2.12), but not with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) and Burkitt lymphoma. The results of this meta‐analysis support a positive link between HBV infection and NHL development. Further investigations for the mechanisms underlying HBV‐induced NHL are warranted.