Table 1.

The common risk factors in HCC

No	Risk factor	Details	Regions	References
1	HBV	Inactivates tumor-suppressing genes	Africa, People’s Republic of China	1–3, 6
2	HCV	Immune response-mediated direct infection that leads to cirrhosis	USA, UK	1–3, 6
3	AFB1	Contamination of staple foods by fungi Aspergillus flavus and Aspergillus parasiticus	Sub-Saharan Africa, Eastern Asia	1, 2, 8
4	Hemochomatosis	Leakage of stored iron to hepatocytes in iron excess more than 5 g	Africa	1, 2
5	HIV	Chronic viral hepatitis	USA	1, 3, 6–9
6	Metabolic syndromes (obesity, diabetes, fatty liver disease)	Increased waist circumstances, particularly BMI more than 30 kg/m2	USA	1–3, 6, 7, 10
7	Tobacco smoking	Smoking cumulatively 11,000 packs of cigarette during the lifetime increases the risk by 1.7-fold	USA	1, 2, 7, 10
8	Alcohol abuse	Excess of 80 g per day more than 10 years increases risk fivefold	USA, Europe	1, 7, 10
9	Mutation in germline DNA	Genetic predisposition to SNPs in EGF	USA	2
10	MOIVC	Obstruction of hepatic venous drainage by complete-clogged lesion	Africa	2
11	Oral contraception	Hepatocarcinogenic properties of oral contraception	USA	2

Abbreviations: HCC, hepatocellular carcinoma; HBV, hepatitis B virus; HCV, hepatitis C virus; AFB₁, aflatoxin B1 exposure; SNPs, single nucleotide polymorphisms; EGF, epidermal growth factor; MOIVC, membranous obstruction of the inferior vena cava; BMI, body mass index.