**2. Risk factors**

HCC has several well-known risk factors, which have been proven to strongly associate with the development of HCC. The most common etiological risk factors are hepatotropic viruses: hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis D virus (HDV) and a suggestive evidence is revealed by similar distribution of HCC in areas where these viruses also encounter increasing incidence and it is considered that up to 90% of the diagnosed HCCs develop in context of hidden cirrhosis [1, 2]. Other risk factors that are highly involved in the hepatocellular carcinogenesis also include autoimmune hepatitis, nonalcoholic fatty liver disease (NAFLD), obesity and diabetes, tobacco and alcohol abuse, environmental toxins, and iron overload.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
