Low prevalence of hepatocellular carcinoma and other liver disease among Greenlanders chronically infected with hepatitis B virus
21 November 2011
In Greenland, 5-10% of the population are hepatitis B surface carriers, reflecting chronic hepatis B virus (HBV) infection. However, the incidence of cirrhosis and hepatocellular carcinoma is low. This discrepancy is now investigated in a large population-based cohort study recently published in the JNCI by researchers from Statens Serum Institut.
Third most common cause of cancer-related death
Hepatocellular carcinoma is a cancer arising from the liver. It is also known as primary liver cancer. Liver cells make up 80% of the liver tissue and the majority of primary liver cancers arises from liver cells. The disease is the third most common cause of cancer-related death worldwide. Thus, it represents a major health problem. One of the most common risk factors for the disease is chronic hepatitis B virus (HBV) infection.
An investigation based on register data
In total, 8,879 Greenlanders (16% of the population) were recruited for population-based studies from May-July 1987 and in November 1998, with follow-up in March 2010. HBV status was determined by serological testing, supplemented by data from all available HBV registries in Greenland to determine changes in HBV status over time. Information on morbidity and mortality was obtained from the Patient Discharge Registry, the Cancer Registry, and the Central Registration System. Incidence rate ratios were estimated using Poisson regression.
Low prevalence of liver diseases despite many chronically HBV-infected
Of the 8,879 study persons, 650 persons were chronically hepatitis B virus (HBV)-infected, and the prevalence of and mortality from liver cancer and other liver diseases among these persons were higher than among the 5,160 HBV-negative study persons. Intriguingly, however, the prevalence of hepatocellular carcinoma and cirrhosis among chronically HBV-infected Greenlanders is low compared with the results from other population-based studies in countries with an equivalently high prevalence of HBV infection.
More benign HBV course in Greenland
The relatively low prevalence of liver cancer and other HBV-related diseases among persons with chronic HBV infection in Greenland indicates a more benign course of HBV among Greenlanders than in other populations in other parts of the world. Possible causes are essentially unknown, but studies of e.g. subtypes of hepatitis B virus in Arctic areas are ongoing.
Read the scientific article
Børresen ML, Koch A, Biggar RJ, Andersson M, Wohlfahrt J, Ladefoged K, Melbye M. Hepatocellular carcinoma and other liver disease among Greenlanders chronically infected with Hepatitis B virus: A population-based study. JNCI 2011;103:1676-1685