Epidemiology of Hepatocellular Carcinoma

Abstract

Liver cancer is a major contributor to the worldwide cancer burden. Incidence rates of this disease have increased in many countries in recent decades. As the principal histologic type of liver cancer, hepatocellular carcinoma (HCC) accounts for the great majority of liver cancer diagnoses and deaths. Hepatitis B virus (HBV) and hepatitis C virus (HCV) remain, at present, the most important global risk factors for HCC, but their importance will likely decline in the coming years. The effect of HBV vaccination of newborns, already seen in young adults in some countries, will be more notable as vaccinated cohorts age. In addition, effective treatments for chronic infections with both HBV and HCV should contribute to declines in the rates of viral-associated HCC. Unfortunately, the prevalence of metabolic risk factors for HCC, including metabolic syndrome, obesity, type II diabetes and non-alcoholic fatty liver disease (NAFLD) are increasing and may jointly become the major cause of HCC globally. Excessive alcohol consumption also remains an intractable risk factor, as does aflatoxin contamination of food crops in some parts of the world. While significant efforts in early diagnosis and better treatment are certainly needed for HCC, primary prevention efforts aimed at decreasing the prevalence of obesity and diabetes and controlling mycotoxin growth, are just as urgently required.

Figure 1.

Global age-adjusted incidence rates of liver cancer, estimated for 2018. Data source: GLOBOCAN 2018. Graph production: IARC (http://gco.iarc.fr/today), World Health Organization.

Figure 2.

Trends in hepatocellular carcinoma incidence rates by country, 1978–1982 through 2008–2012. Rates are per 100,000 person-years and age-adjusted to the world standard population.