Obesity is now affecting both adults as well as children, even in developing countries. Extensive epidemiological studies have demonstrated a definite connection between obesity and the development and progression of different types of cancers, which is true even for liver cancer. Obesity is associated with liver diseases like non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). NASH, characterized by fatty liver inflammation, causing fibrosis and cirrhosis, is itself a risk factor for liver cancer. 

Since obesity has a much higher prevalence, it may be a more valuable contributor to the overall hepatocellular carcinoma burden than infection with hepatitis viruses. 

Obesity is involved in HCC development as it causes lipid accumulation within hepatocytes leading to chronic low-grade liver inflammation, involving various cytokines and adipokines. Although some of the cytokines and adipokines that contribute to the onset of steatohepatitis and the initiation and promotion of HCC are known. Yet, the effect of hepatosteatosis on genetic instability inside hepatocytes, controlling mechanism of hepatosteatosis progression to steatohepatitis and ways by which chronic steatohepatitis causes tumor initiation, still demands an answer. Although weight loss by bariatric surgery, diet or exercise has shown to reduce obesity-induced metabolic syndromes, more effective therapeutic interventions needs to be recognized to prevent the development and progression of HCC.

Source: Sun B, Karin M. Obesity, inflammation, and liver cancer, Journal of Hepatology, 2012;56(3): 704-713. https://doi.org/10.1016/j.jhep.2011.09.020.