TAIPEI, Taiwan and PRINCETON, N.J., Jan. 3 /PRNewswire/ -- Chronic hepatitis B patients with high levels of circulating hepatitis B virus (HBV) appear to be at increased risk of developing liver cancer (specifically, hepatocellular carcinoma), independent of other known risk factors, according to a paper published in The Journal of the American Medical Association. The R.E.V.E.A.L.-HBV Study (Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer-HBV Study), one of the largest and longest natural history studies of hepatitis B, evaluated the relationship between levels of hepatitis B virus in the blood and risk of liver cancer. Between 1991 and 1992, a total of 3,653 people diagnosed solely with chronic hepatitis B infection were recruited from seven townships in Taiwan. Patients were followed until the middle of 2004, for a mean of 11.4 years.
“Our findings suggested a strong relationship between a patient’s hepatitis B virus level and his or her long-term risk of developing liver cancer,” said Professor Chien-Jen Chen, ScD, Graduate Institute of Epidemiology, College of Public Health, National Taiwan University.
The rate of liver cancer increased with elevated hepatitis B virus levels at study entry independent of other risk factors, including e-antigen status, serum alanine aminotransaminase (ALT), and presence of liver damage (or cirrhosis). The study also confirmed other known risk factors that influence the probability of HBV-related liver cancer, including: male gender, old age, infection with e-antigen positive virus, alcohol consumption, and the presence of cirrhosis.
The study demonstrated that the risk of liver cancer started to increase significantly at virus levels greater than or equal to 10(4) copies/mL. Patients with hepatitis B virus levels measuring between greater than or equal to 10(4) and <10(5) copies/mL at enrollment had more than a two times higher relative risk of liver cancer compared to study participants with undetectable virus levels (cumulative incidence of 3.57 percent versus 1.3 percent, respectively). Another important conclusion of this study was that patients with persistently elevated hepatitis B virus levels (i.e., greater than or equal to 10(5) copies/mL at both study entry and last observation) had a greater than five times relative risk for liver cancer compared to patients with hepatitis B virus levels <10(4) copies/mL at study entry. This risk fell to less than two times in patients whose hepatitis B virus levels decreased from 10(5) to <10(4) copies/mL at last observation when compared to patients with hepatitis B virus levels <10(4) copies/mL at study entry.
Influence of HBV genotype was not evaluated in this study, and is likely to be addressed in future studies.
Globally, more than 350 million individuals are chronically infected with the hepatitis B virus. For those who are infected, the risk of HBV-related liver cancer ranges from 5 to 98 times higher than those who are not infected. Chronic hepatitis B is particularly endemic in Taiwan, where the infection is usually acquired at birth or in early childhood. Chronically infected people are known to be at an increased risk of developing liver cirrhosis, hepatic decompensation and liver cancer, and 15 to 40 percent of them will develop these serious disease complications during their lifetime. Data from this study showed that among all the risk factors assessed, the level of circulating hepatitis B virus had a strong predictive value for progression to liver cancer.
The R.E.V.E.A.L.-HBV study authors are affiliated with the Graduate Institute of Epidemiology, College of Public Health, National Taiwan University; Global Epidemiology and Outcomes Research, Bristol-Myers Squibb Company; Department of Gastroenterology, Kaohsiung Chang-Gung Memorial Hospital; Department of Internal Medicine, National Taiwan University Hospital.
National Taiwan University is a leading research university in Taiwan. Visit National Taiwan University on the World Wide Web at http://www.ntu.edu.tw.
Bristol-Myers Squibb is a global pharmaceutical and related health care products company whose mission is to extend and enhance human life. Visit Bristol-Myers Squibb on the World Wide Web at http://www.bms.com.
Bristol-Myers Squibb Company
CONTACT: Kathy Baum of Bristol-Myers Squibb, +1-609-252-4227; or Chien-JenChen of National Taiwan University, +886-2-2393-8683,cjchen@ha.mc.ntu.edu.tw
