What
is Hepatitis B? > Your Liver > Hepatitis B and Primary
Liver Cancer
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 hepatocellular 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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