Epidemiology

Hepatitis B genotype C linked to increased hepatoma risk

Last Updated: 2013-01-25 17:25:09 -0400 (Reuters Health)

By Will Boggs, MD

NEW YORK (Reuters Health) - Of all the major hepatitis B virus (HBV) genotypes, genotype C carries the highest risk for hepatocellular carcinoma (HCC), Chinese researchers say.

"These findings are useful when we decide the need of antiviral therapy and intensity of HCC surveillance," Dr. Grace L.-H. Wong from The Chinese University of Hong Kong told Reuters Health. "The treatment threshold for patients infected by genotype C HBV should be probably lower than (for) those infected by other genotypes. Also patients infected by genotype C HBV should have more frequent HCC screening tests."

As reported online January 10 in Alimentary Pharmacology and Therapeutics, Dr. Wong and colleagues used a meta-analysis of 43 studies involving 14,545 patients to investigate the relative risk of HCC among the four major HBV genotypes (A, B, C, and D).

In the 33 studies with data on patients with genotypes B and C, HCC occurred about twice as often with genotype C HBV as with genotype B HBV (25% vs 13%; p<0.001).

HCC rates did not differ significantly between genotypes A and D (14% vs 11%; p=0.71), in the 12 studies that compared them.

Ten studies included patients with genotypes A and/or D and genotype C. In these, HCC rates were significantly higher with genotype C (30% vs 7%; p<0.001).

In eight studies, there was no significant difference in HCC risk between subgenotypes Ce and Cs (41% vs 28%; p =0.54).

"Nowadays the risk factors of HCC have been quite well-established," Dr. Wong said. "In the future we should look for some markers which are useful to achieve early diagnosis of HCC with high sensitivity and specificity."

"We plan to study the effect of HBV genotype on the treatment outcome of HCC patients, namely if they affect the risk of HCC recurrence after treatment," Dr. Wong said. "We also would like to investigate the effect of antiviral therapy in patients infected by different genotypes, namely whether the antiviral therapy would reduce the risk of hepatic events and HCC more in one HBV genotype than the others."

"The impact of HBV genotypes on the course of liver disease and also on antiviral therapy has been (and is discussed) controversially," Dr. Claus-Thomas Bock from Robert Koch Institute's Head of Molecular Epidemiology of Viral Pathogens, Berlin, Germany, told Reuters Health by email.

He continued, "Unlike hepatitis C virus (HCV) therapy, where the impact of HCV-genotypes on clinical course and antiviral therapy (IFN) has been accepted and the diagnosis of HCV genotypes is more or less routine, the costly and time-consuming diagnosis of HBV genotypes seemed to be dispensable for most of the doctors."

"In the present study it has been shown that HBV genotype C infected patients might have a reasonable and higher risk for the development of severe hepatitis and HCC," Dr. Bock said. "These patients should be therefore monitored more closely for signs of HCC development and should be considered for antiviral therapy (with nucleoside/nucleotide analogues)."

He noted that HBV genotype C infection is prevalent in Asians. It may be that HBV genotyping should be done only in this population, he indicates. But in general, Dr. Bock advises, in patients with hepatitis B surface antigen and risk factors for HCC (like HBV genotype C), "lifelong surveillance for HCC with biochemical testing and ultrasound examination at close intervals" is warranted.

SOURCE: http://bit.ly/WWozdS

Aliment Pharmacol Ther 2013.