Chronic hepatitis B virus infection and the risk of hepatocellular carcinoma by age and country of origin in people living in Sweden: A national register study

Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC), and surveillance is recommended for patients without cirrhosis when risk exceeds an incidence rate (IR) of 0.2%. Populations in Asia and sub-Saharan Africa have been associated with HCC at younger ages, but the risk after immigration to Western countries should be investigated. The aim of this study was to study HCC by age and country of origin in people with chronic HBV infection in Sweden. Through national registers, residents with chronic HBV diagnosis (1990-2015) were identified with information on country of origin, immigration/emigration, death, coinfections, antiviral therapy, and HCC. Observation time started at HBV diagnosis, and IR and hazard ratios for HCC were calculated by sex, age, and region of origin. Among 16,410 individuals (47% women), the origin and observation time (person years) were as follows: Western Europe, 2316 (25,415); Eastern Europe, 2349 (26,237); Middle East/North Africa, 4402 (47,320); sub-Saharan Africa, 3677 (30,565); Asia, 3537 (35,358); and other, 129 (1277). There were 232 individuals with HCC (82% in men). The IR increased with age and exceeded 0.2% for Asian men from age group 40-49 years (IR, 0.63; 95% confidence interval, 0.39-1.00), for men of other origins from age group 50-59 years, and for women aged >= 60 years originating from Eastern Europe, Asia, and Middle East/North Africa. After exclusion of patients with cirrhosis or HBV treatment, the IR still exceeded 0.2% in Asian men aged 40-49 years. This study demonstrates that HBV-infected men of Asian origin should be recommended HCC surveillance at younger ages, but there is a need for further studies of HCC incidence in African-born men without cirrhosis living in the Western world.