To Örebro University

OBJECTIVE: The aim of this nationwide cohort study was to assess the risk for hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection or HBV and hepatitis C virus (HCV) co-infection in Sweden, a low endemic country.

MATERIAL AND METHODS: A total of 12,080 patients with HBV and 3238 patients with HBV-HCV co-infection were notified to the Swedish institute for Infectious Disease Control between 1990 and 2004. After excluding 1850 patients with acute HBV and 584 patients infected in adult life, we analyzed the cohort of 9646 subjects with chronic HBV infection. In the co-infection cohort, 1697 patients were analyzed after excluding 1541 cases with acute HBV. The Swedish national cancer registry was used for follow-up. The HCC incidence rate in the cohorts was compared with the HCC incidence rate in the general population and the standardized incidence ratio (SIR) was calculated for different strata according to estimated infection period.

RESULTS: HCC was found in 45 patients in the HBV cohort. In the stratum of 40-49 years of infection we found a SIR of 47 and in stratum 50-59 years the SIR was 54. In the co-infected cohort 10 HCCs were found. The SIR in the stratum 20-29 years of infection was 34 and the SIR in the stratum 30 years and over was 91.

CONCLUSIONS: This national cohort study of HBV infected and HBV-HCV co-infected subjects in a low endemic country confirms a highly increased risk of liver cancer compared to the general population.