Liver and bile duct cancers affect many older Americans. In fact, the average age at diagnosis for liver cancer is 64. But what causes this debilitating disease? And who is at risk for developing liver cancer?

What does the liver do?
The liver is the largest organ inside the body and it lies under the right ribs, just below the right lung. The liver has many vital functions that you cannot live without including:

• Bile secretion into the intestine to help absorb nutrients
• Break down of nutrients absorbed from the intestine
• Creation of clotting factors needed to stop bleeding
• Removes waste from the body
• Storage of nutrients

What is liver cancer?
Liver cancer is a cancer that starts in the liver. Liver cancer occurs when liver cells develop changes (mutations) in DNA and begin to grow out of control. A cancer is a mass of malignant cell growth that can invade and damage nearby tissues and organs (such as the stomach or intestine), can spread to other parts of the body, or can be a threat to life.

Types of liver cancer
Because the liver is made up of different types of cells, many types of tumors can form in the liver. Some of these are cancer and some are not. For example, benign tumors of the liver can sometimes grow large enough to cause problems. Cancer that starts in the liver is called primary liver cancer, or hepatocellular carcinoma (HCC). Cancer that spreads to the liver from another organ is called metastatic liver cancer.

1. Benign liver tumors
2. Primary liver cancer - hepatocellular carcinoma
3. Secondary liver cancer - metastic

Benign liver tumors

Focal nodular hyperplasia (FNH) - FNH is a tumor-like growth of several cell types that are benign.

Hemangiomas - These are the most common type of benign liver tumor and start in blood vessels.

Hepatic adenomas - These benign tumors start from the main type of liver cells (hepatocytes)

Primary liver cancers

Angiosarcomas and hemangiosarcomas - These rare forms of cancer start in the blood vessels of the liver and tumors grow quickly.

Cholangiocarcinomas (bile duct cancers) - These cancers start in the small tubes that carry bile to the gallbladder (bile ducts).

Hepatoblastoma - A rare type of liver cancer that usually develops in children younger than 4 years old.

Hepatocellular carcinoma (HCC) - This is the most common form of liver cancer in adults. HCC begins in the hepatocytes, the main liver cell and can have different growth patterns. Some begin as a single tumor that grows larger and later spreads to other parts of the liver. This type of cancer may also begin in many spots throughout the liver, not as a single tumor.

Although doctors are not quite clear on the exact causes of liver cancer, there are certain risk factors which you can avoid. Click here to learn more about possible links between liver cancer and liver disease.