Liver Cancer

Liver cancer is a disease in which malignant (cancer) cells form in the tissues of the liver. It is the fifth most common malignancy in men and the eighth in women worldwide. In the United States, liver cancer is not common, but the incidence has been increasing in the last decade. By contrast, the incidence in some high-risk countries (such as Taiwan) has decreased, possibly due to the introduction of the hepatitis B virus vaccine.

Symptoms and Diagnosis

The following symptoms may be caused by liver cancer or by other conditions:

• A hard lump on the right side just below the rib cage.
• Discomfort in the upper abdomen on the right side.
• Pain around the right shoulder blade.
• Unexplained weight loss.
• Jaundice (yellowing of the skin and whites of the eyes).
• Unusual tiredness.
• Nausea.
• Loss of appetite.

To diagnose liver cancer, the following tests and procedures may be used:

• Physical exam and history.
• Complete blood count (CBC).
• Serum tumor marker test.
• Laparoscopy.
• Biopsy.
• CT scan (CAT scan).
• MRI (magnetic resonance imaging).
• Ultrasound.

Causes

All cancers are caused by dysfunctions of proteins involved in cell division, apoptosis, or DNA repair (see general characteristics). Dysfunctional proteins may arise from gene mutations or protein interaction with environments such as viral proteins.  The following risk factors may increase the chance of developing liver cancer:

• Infection with hepatitis B or C virus
  This factor accounts for over 80% of liver cancer cases worldwide. The X protein (HBx) of hepatitis B virus is known to play a key role in the development of liver cancer, but the exact mechanism is not clear (more info). The carcinogenic property of hepatitis C virus is associated with its NS5A protein which may inhibit apoptosis.
• Exposure to Aflatoxin B₁
  Aflatoxin is produced by fungi on nuts and grains that have not been stored properly. Aflatoxin B₁ may cause p53 mutation (more info).
• Having cirrhosis
  Cirrhosis is a chronic, progressive liver disease in which liver cells are replaced by scar tissue. It may be caused by alcohol abuse.

Treatment

Localized Resectable Liver Cancer

• Partial removal of the liver.
• Total removal of the liver and liver transplant.

Localized and Locally Advanced Unresectable Liver Cancer

• Cryosurgery or radiofrequency ablation.
• Chemotherapy.
• Percutaneous ethanol injection.
• Total removal of the liver and liver transplant.
• Radiation therapy with radiosensitizers.

Advanced Liver Cancer

There is no standard treatment for advanced adult primary liver cancer. Patients may consider taking part in a clinical trial. Treatment may be a clinical trial of biologic therapy, chemotherapy, and/or radiation therapy with or without radiosensitizers. These treatments may be given as palliative therapy to help relieve symptoms and improve the quality of life.

Reference:

National Cancer Institute, USA.