RSS feedHepatocellular carcinoma (HCC or primary liver cancer) is common in Asia because of the high incidence of hepatitis B virus (HBV) chronic infection in the population. However, in some countries such as Japan and southern part of Taiwan, hepatitis C virus (HCV) infection has become more prominent than HBV as a causative agent for HCC. Chronic HBV and HCV infection can lead to cirrhosis (hardening of the liver) and HCC. HBV carriers have a 100-fold increased risk of HCC relative to those without HBV infection. About 2.1% of HBV carriers develop cirrhosis each year. The annual incidence of HCC in patients with cirrhosis is 3 – 10% (J Gastroenterol Hepatol 2000; 15 Suppl: E25 – E30). Immunisation will help prevent HBV but not HCV infection. Its effectiveness in reducing the incidence of HCC has been well proven in Taiwanese children. In 1984, a mass neonatal vaccination programme against HBV was launched in Taiwan in order to control the incidence of perinatal HBV infection. The HBV carrier rate decreased from the historical 15 – 20% to < 1% after vaccination and the annual incidence of childhood HCC has decreased from 0.67 to 0.19 / 100,000 children (Hepatol Res 2007; 37 Suppl 2: S101 – S105). What happens if you are already an HBV / HCV carrier and you happen to be obese and/or suffer from diabetes? Is your risk of HCC lower or higher?
A recent study from the National Taiwan University followed 23,820 Taiwanese residents for 14 years to see if obesity, diabetes and other metabolic factors were independently associated with HCC (Gastroenterology 2008; 135: 111 – 121). The HBV and HCV status of all these residents were determined at enrollment. Extreme obesity (BMI ≥ 30 kg / m2) was independently associated with a 4 – fold increased risk of HCC in those with HCV infection but not in HBV infected individuals. If you are neither HBV nor HCV infected but you are extremely obese, you have a 2-fold increased risk of developing HCC. If you are HCV infected and suffer from diabetes, your risk of developing HCC is increased by 3.52 times. In the case of HBV, the risk is increased by 2.27 times. If you are both obese and diabetic, the risk is increased > 100 fold for both HBV and HCV carriers. This finding implies synergistic effects of metabolic factors and hepatitis infection.
Obese individuals have a higher risk of developing diabetes mellitus. If you are an HBV / HCV carrier, you have a very strong incentive not to get overweight and increase the risk of developing diabetes mellitus. At present, we are not able to cure a significant number of HBV or HCV carriers with medication; thus, it is important for all carriers to reduce their risk of developing HCC on top of their hepatitis infection. Staying trim and healthy will certainly help!
