The known risk factors for hepatocellular liver cancer are: hepatitis B virus, hepatitis C virus (HBV, HCV) infection, alcohol abuse, smoking and aflatoxin use. Possible risk factors are: food, obesity, diabetes, insulin resistance, use of oral contraceptives, and iron overdose.
1. Aflatoxin
Aflatoxin is a mycotoxin produced by Aspergillus flavus and Aspergillus parasiticus, which can cause liver cancer in a variety of experimental animals. The contamination mainly originates from improper food storage and is prevalent in Africa, Southeast Asia and China.
Using a prospective study approach, a close relationship between biomarkers of aflatoxin in body fluids and secondary hepatocellular carcinoma was shown.
Aflatoxin B1 (AFB1) causes a G:C to T:A transition at the third base of codon 249 of P53. HBV alone cannot affect the frequency of mutations, but in the presence of AFB1, it can make the mutation frequency much higher. Therefore, the oncogenic effect of AFB1 is related to the process of HBV infection.
2.Drinking alcohol
Alcohol consumption is an important risk factor leading to the high incidence of liver cancer. Especially in developed countries, its role is more obvious.
Using meta-analysis, it is shown that there is a positive dose-dependent relationship between alcohol intake and relative risk factors (RR) for liver cancer, i.e., the RR value increases with higher alcohol intake, and there is no safety threshold for the effect of alcohol on the liver.
The effect of alcohol on liver cancer may proceed through cirrhosis. Also HCV can accelerate the action of alcohol on liver cancer. Further there is a synergistic effect between alcohol intake, smoking, obesity and diabetes.
3. Smoking
Using meta-analysis showed that relative never smokers, former and current smokers were more likely to develop liver cancer, while the relative risk factors of smoking for liver cancer were stable in the overall.
The synergistic relationship between smoking and HBV/HCV infection is not very clear.
4.Dietary factors
Coffee may have the effect of reducing the incidence of liver cancer, but there are some biases in some studies on coffee, and further confirmation of the effect of coffee alone and its combined effect with other factors on liver cancer is needed.
Some studies suggest that vegetables, fruits, dairy products, white meat, and eggs may have a protective effect on the liver, but overall there are relatively few studies in this area, so the evidence is not conclusive.
The current studies on dietary factors are retrospective, but this approach is not reasonable for patients with chronic diseases, including liver cancer.
5. Obesity and diabetes mellitus
Obesity and diabetes are both risk factors for HCC.
Obesity may be caused by fatty liver or non-alcoholic fatty liver (NASH) and lead to HCC. Diabetes is secondary to sclerosis caused by HCC, or its own direct cause of HCC susceptibility, there is still a lot of controversy. The duration of diabetes and the effect of treatment on HCC risk factors also need to be studied.
6.Oral contraceptive pills
Oral contraceptives can significantly increase the risk factors for hepatic adenoma. It may slightly increase the risk of hepatocellular carcinoma in patients with a relatively low rate of HBV infection.
The duration of oral contraceptive use, intervals, recent use, the effect of HBV/HCV, and the effect of some other factors need further study.
7.Iron overdose
Iron overdose may raise the risk of HCC.
The effect of iron overdose may not be related to sclerosis, but may be related to alcohol consumption and HBV/HCV infection.