Hepatocellular carcinoma is one of the most commonly occurring tumors in the world. This form of cancer is the fifth most common malignancy in men and the eighth most common in women.
The epidemiology of this cancer occurs as two main patterns – the one seen in North America and Western Europe and the one seen in non-Western regions such as sub-Saharan Africa, the Amazon basin and central and Southeast Asia.
This cancer usually affects people between the ages of 30 and 50 and causes around 660,000 deaths across the globe every year. About half of these deaths occur in China.
Hepatocellular cancer is the most common form of cancer in sub-Saharan Africa and Southeast Asia and usually affects people between the teenage years and age 40. The increased prevalence in these regions is due to the relatively high transmission of hepatitis C and hepatitis B compared with Western countries.
Infection with these viruses at birth predisposes to an earlier onset of the cancer than when individuals become infected at an older age. It can take years or even decades for hepatitis to progress to hepatocellular cancer, but once the cancer develops, the average survival time is only 5.6 months in China and 3 months in sub-Saharan Africa. In Japan, chronic hepatitis C is associated with 90% of hepatocellular carcinoma cases. Food infected with Aspergillus flavus is also another risk factor for the condition.
In these regions, hepatocellular carcinoma usually occurs as secondary to liver disease. The main risk factors for hepatocellular cancer in these countries are hepatitis B, hepatitis C, cirrhosis and hemachromatosis.