Risk Factors and Causes of Liver Cancer

Liver cancer may not have as high a profile as some other forms of cancer but it is one of the most lethal forms of cancer. Most people do not survive beyond a year after being diagnosed with it. A peculiar fact about liver cancer is that its risk factors are mostly related to lifestyle choices and behavior such as alcohol use, sexual behavior, drug abuse, and occupation.

The most common risk factor/cause of liver cancer is spread from other cancer sites in the body (metastasis) but this causes Secondary liver cancer. The risk factors that are discussed here are those that result in Primary liver cancer which is cancer that originates in the liver.

Risk Factors for Liver Cancer

Sex: Liver cancer occurs more in males than females. This could be attributed to the fact that males are more likely to engage in behavior that predispose to developing liver cancer such as excessive alcoholic intake and use of anabolic steroids. (1) (2)

Age

Cancer of the liver is more common in older people in developed regions of the world. In contrast, it occurs more in younger persons in developing areas like Africa and Asia. (2)

Hepatitis

Chronic infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) both lead to cirrhosis and consequently, liver cancer. HCV infection is more likely to become chronic and is the more common cause of liver cancer in developed areas like the United States. HBV is the more prevalent risk factor in developing regions. Both viruses are transmitted through such means as unprotected sex, sharing needles (drug abusers) and contaminated blood transfusions. (1) (2) (3) (4)

Excessive Alcohol Intake

Prolonged alcohol abuse leads to irreversible liver damage and consequently, liver cirrhosis and liver cancer. (2) (4)

Aflatoxins

These are substances produced by fungi which grow on food such as wheat, corn, rice, peanuts, etc. Eating food contaminated with aflatoxins over a long period of time increases the risk of liver cancer. (1) (2) (3) (4)

Prolonged Use of Anabolic Steroids

Anabolic steroids are hormones used to increase muscle bulk by athletes and body builders. Long-term use increases the risk of liver cancer. (1) (3) (4)

Non-Alcoholic Fatty Liver Disease

In this condition, fats called triglycerides accumulate in the liver. It is seen in diabetic patients and obese people and leads to cirrhosis. It is associated with an increased risk of liver cancer. (1) (2) (4)

Exposure to Chemical Compounds:

Certain chemical compounds greatly increase the risk of liver cancer. They include vinyl chloride which is used in making plastics and arsenic which is found in water from some wells. Prolonged exposure to these compounds increases the risk of developing liver cancer. (1) (3) (4)

Liver Cirrhosis

Liver cirrhosis is the end result of several types of insult to the liver and is one of the most important risk factors for liver cancer. In this condition, damaged liver cells are replaced by non-functioning scar tissue. Cirrhosis can be caused by obesity, alcohol abuse, hepatitis infection, non-alcoholic fatty liver disease, autoimmune diseases, and metabolic diseases of the liver. (1) (2) (3)

Smoking

This has not been totally proven but some scientists say there is a link between smoking tobacco and an increased risk of liver cancer. The effect of smoking is seen to be more pronounced in people who have hepatitis or abuse alcohol. (1) (3) (4)

Immunosuppression

Depressed immunity such as in people who suffer from HIV/AIDS or in transplant patients who take immunosuppressive medication can lead to an increased risk of developing liver cancer. This may be because they are more likely to be infected with hepatitis viruses. (3)

Contraceptive Pills

That contraceptive pills increase the risk of developing liver cancer is still a controversial issue. Contraceptive pills have been found to cause benign liver tumors called hepatic adenomas but it is not clear if this increases the risk of liver cancer. (1) (3)

Obesity

Studies have shown that liver cancer occurs more in overweight and obese people. This could be because obesity can lead to non-alcoholic fatty liver disease and liver cirrhosis which are both risk factors for liver cancer. It could also be related to diabetes as diabetic people are commonly overweight. (1) (2) (3) (4)

Family History

A history of liver cancer in other family members especially first-degree relatives like a parent or sibling increases the risk of a person developing liver cancer. Other forms of cancer e.g. prostate cancer in such a relative may also increase this risk. (3)

Diabetes

Research has shown that people who suffer from diabetes are more prone to developing liver cancer than those who do not. Diabetes increases the risk two- to threefold. Diabetes is also associated with non-alcoholic fatty liver disease and obesity. (1) (2) (3) (4)

Inherited Metabolic Diseases

These are rare diseases present at birth which cause an increased risk of liver cancer. An example is Hemochromatosis in which the body absorbs too much iron from food leading to liver cirrhosis. Other such conditions include Wilson’s disease, porphyria cutanea tarda, tyrosinemia, and glycogen storage diseases. (1) (2) (4)

Sources:

1. What the Risk Factors for Liver Cancer?

http://our.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_liver_cancer_25.asp

2. Liver Cancer: Risk Factors

http://www.mayoclinic.com/health/liver-cancer/DS00399/DSECTION=risk-factors

3. Risks and Causes of Liver Cancer

http://www.cancerhelp.org.uk/type/liver-cancer/about/risks-and-causes-of-liver-cancer

4. Liver Cancer: Risk Factors and Prevention

http://www.mskcc.org/mskcc/html/271.cfm