Chronic hepatitis B is associated with an increased risk of B-cell non-Hodgkin's lymphoma and multiple myeloma

Background Chronic hepatitis B has been linked to lymphoma with contradictory results. Aim To investigate the association between chronic hepatitis B and lymphoma by using a nationwide population-based cohort. Methods Records of patients diagnosed with chronic hepatitis B (hepatitis B virus [HBV] cohort) or without (non-HBV cohort) during 2004-2007 were retrieved from the Taiwan National Health Insurance Research Database. Age, sex, comorbidities, and medical visits were matched using propensity scores between both cohorts, and they were followed up longitudinally until 2012 to determine any new lymphoma development. Results A total of 203 031 patients were included in each cohort with a mean follow-up of 7-9 years. The lymphoma incidence rate was significantly higher in the HBV cohort than in the non-HBV cohort (29.4 vs 15.9 per 100 000 person-years, P < 0.0001). After adjustment for comorbidities and medical visits, HBV infection was found to be an independent risk factor associated with the development of lymphoma (hazard ratio [HR]: 2.07, 95% confidence interval [CI]: 1.76-2.43, P < 0.0001) and non-Hodgkin's lymphoma (HR: 2.18, 95% CI: 1.80-2.65, P < 0.0001); specifically with an increased risk of diffuse large B-cell lymphoma (HR: 2.69, 95% CI: 2.05-3.52, P < 0.0001), other B-cell lymphoma (HR: 3.11, 95% CI: 1.89-5.11, P < 0.0001), and also for multiple myeloma (HR: 1.63, 95% CI: 1.10-2.42, P = 0.016). The association was significant even after excluding lymphoma development within the first year (HR: 2.08, 95% CI: 1.75-2.47, P < 0.0001). Conclusions Chronic hepatitis B is temporally associated with a 2-fold increased risk of lymphoma, particularly with B-cell non-Hodgkin's lymphoma, and also an increased risk for multiple myeloma.