Friday, June 22, 2012

Hepatitis B and Primary Liver Cancer

Chronic hepatitis B infections cause 80% of all primary liver cancer worldwide.
Patients with chronic hepatitis B infections are at increased risk for progressing to liver cancer or hepato cellular carcinoma (HCC), whether they develop cirrhosis or not.

In the U.S. the overall incidence of cancer is decreasing, except for primary liver cancer (as reported by the National Cancer Institute in 2005). This is due in large part to the increased number of Americans who are chronically infected with hepatitis B and hepatitis C. Although survival rates for most types of common cancers have improved over the years, the 5-year survival rate for liver cancer is still below 10%.

In the world, primary liver cancer is the 3rd leading cause of death. According to the World Health Organization, at least 550,000 people die each year from primary liver cancer.
The hepatitis B vaccine was named the first "Anti-Cancer Vaccine" vaccine by the U.S. Food and Dug Administration since it prevents hepatitis B infections, the leading cause of primary liver cancer.

Who should be screened for liver cancer?
Early detection improves the chances of survival after treatment. Since liver cancer develops quietly, usually without symptoms, patients with chronic hepatitis B should undergo regular liver cancer screening. A reasonable approach is to begin regular liver cancer screening at 30 years of age (although experts are recommending starting an even earlier age since liver cancer can strike children, though rare).


It is important to stress that Asians and Asian Americans, who generally develop chronic hepatitis B infections soon at birth, have a high risk of developing liver cancer at an early age whether they have cirrhosis or not. The risk is greater in men and those with a positive family history for liver cancer.

What is liver cancer screening?
This generally consists of a simple blood test for alpha-fetoprotein (AFP) levels every 6 months and an ultrasound of the liver at least once a year. Either test alone can miss the diagnosis. Some doctors prefer CT scans to ultrasounds. Once the patient develops cirrhosis, or has a family history of liver cancer, more frequent screening is generally recommended.

What are the symptoms of liver cancer?
Liver cancer is a silent killer because the majority of patients appear to be perfectly healthy and have no early signs or symptoms. Both small and large tumors may be undetected due to the shielded location of the liver underneath the ribs.
Pain is uncommon until the tumor is quite large, and some large tumors don't even cause pain or any symptoms. Later stages of liver cancer, when the cancer is very large or when it impairs the functions of the liver, can produce more obvious symptoms such as abdominal pain, weight loss, lack of appetite, and finally the development of jaundice and abdominal swelling.

How is liver cancer treated?
Treatment of HCC is particularly challenging when compared with other types of cancer because in addition to the cancer itself, many patients have livers that have been damaged by chronic hepatitis B infections. For each individual patient, the potential benefits of the various treatment options must be balanced with the risk of liver failure and how it affects the patient's quality of life.

Surgical Treatment - When the tumor is small and the patient's liver condition is stable, surgical removal offers the best chance for long-term survival. Despite complete removal of the tumor, however, patients are still at risk for recurrent disease. They will need to be followed closely long-term, especially during the first year when the risk of recurrence is greatest.
Nonsurgical Treatment - For patients who cannot undergo surgery, a number of treatment options, though limited in effectiveness, are available or being investigated in an attempt to control the disease long-term and with the aim of maintaining normal quality of life. Traditional chemotherapy is generally ineffective, causes many side effects that may severely impair the patient's quality of life, and often does not prolong survival.

TACE (or TAC) - Since HCC are hypervascular tumors often fed by one or more blood vessels from the hepatic arteries, they present the unique opportunity to target the therapy directly into the tumor. Intrahepatic arterial chemoembolization or chemoinfusion (TACE or TAC) is used in the treatment of selected patients with tumors that cannot be surgically removed.
Long-term treatments with TACE or TAC have been associated with prolonged patient survival, and those who have good control or shrinkage of the tumor may even become suitable candidates for surgical resection or transplantation.

What about a liver transplant?
Liver transplant is the only treatment option for patients with liver cancer tumors that cannot be surgically or medically removed. The tumor must be small (less than 5 cm or fewer than 4 lesions), confined to the liver, and without invasion into the blood vessels. Larger or more extensive tumors have a high risk for early recurrence after liver transplantation.

What does the future hold?
Early diagnosis of small tumors is the only effective way of improving the outcome of liver cancer treatment, and that is only possible through screening of the high-risk population. Universal hepatitis B vaccination is ultimately the only hope for reducing the incidence of this frequently fatal cancer worldwide.

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