Saturday, October 2, 2010

Can Liver Cancer Be Found Early?


Can Liver Cancer Be Found Early?

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Prevalence and Challenges of Liver Diseases in Patients with Chronic Hepatitis C Virus Infection : Discusses disease progression, fibrosis, cirrhosis and liver cancer in the HCV population.
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Chronic viral hepatitis

The most common risk factor for liver cancer is chronic (long-term) infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). These infections lead to cirrhosis of the liver (see below) and are responsible for making liver cancer the most common cancer in many parts of the world.

In the United States, infection with hepatitis C is the most common cause of HCC, while in Asia and developing countries, hepatitis B is more common. People infected with both viruses have a very high risk of developing chronic hepatitis, cirrhosis, and liver cancer.

HBV and HCV are spread from person to person through sharing contaminated needles (such as in drug use), unprotected sex, or childbirth. They can also be passed on through blood transfusions, although this is rare in the United States since the start of blood product testing for these viruses. In developing countries, children sometimes contract hepatitis B infection from prolonged contact with family members who are infected.

Of the 2 viruses, infection with HBV is more likely to cause symptoms, such as a flu-like illness and a yellowing of the eyes and skin (jaundice). But most people recover completely from HBV infection within a few months. Only a very small percentage of adults become chronic carriers (and have a higher risk for liver cancer). The risk is higher in infants and small children who become infected.

HCV, on the other hand, is less likely to cause symptoms. But most people with HCV develop chronic infections, which are more likely to lead to liver damage or even cancer.

Other viruses, such as the hepatitis A virus and hepatitis E virus, can also cause hepatitis. But people infected with these viruses do not develop chronic hepatitis or cirrhosis, and are not at an increased risk of liver cancer.
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Can Liver Cancer Be Found Early?

Because signs and symptoms of liver cancer do not usually appear until it is in its later stages, it is seldom diagnosed early. Small liver tumors are hard to detect on a physical exam because most of the liver is covered by the right rib cage. By the time a tumor can be felt, it may already be quite large.

Many patients who develop liver cancer have long-standing cirrhosis (scar tissue formation due to liver cell damage). If a patient with cirrhosis gets worse for no apparent reason, doctors should suspect that liver cancer may be the cause and do appropriate tests.

If a person is known to have cirrhosis, whatever the cause, most doctors recommend liver cancer screening every 6 months with tests of alpha-fetoprotein (AFP) and ultrasound. But it's not yet clear if screening will result in more effective treatment of liver cancer.

Alpha-fetoprotein blood test
Alpha-fetoprotein (AFP) is a protein that is normally present at high levels in the blood of fetuses but disappears shortly after birth. If it is found in the blood of adults, it suggests they may have liver cancer or some types of germ cell tumors of the testicle (in men) or ovary (in women). It can also be found in the blood of pregnant women and can be used to help diagnose some birth defects and other problems with the fetus before birth.

Tests for AFP are used to look for early tumors in people at high risk for liver cancer. But it is usually not advised as a routine test to screen for liver cancer in people at average risk because there are potential problems with using it:

Some liver tumors do not make a lot of this protein.
Often by the time the AFP level is elevated, the tumor is too large to be removed or it has spread outside the liver.
Some non-cancerous liver diseases can also raise AFP levels.
In areas where liver cancer is very common, using the AFP blood test for screening has detected many tumors at an earlier stage. Still, many experts feel that AFP testing isn't sensitive enough for people living in the U. S. and Europe, and recommend ultrasound (see the next section) as the main test, although the AFP level may still be measured along with it.

Ultrasound
Ultrasound is a test that uses sound waves and their echoes to produce a picture of internal organs or masses. A small instrument called a transducer emits sound waves and picks up the echoes as they bounce off the organs. The echoes are converted by a computer into a black-and-white image that is displayed on a video screen. This test can show masses (tumors) growing in the liver, which can then be tested for cancer, if needed.

This is a very easy procedure to have. It uses no radiation, which is why it is often used to look at developing fetuses. For most ultrasound exams, you simply lie on a table while the transducer (which is shaped like a wand) is placed on the skin over the part of your body being looked at. Usually, the skin is first lubricated with gel.

This test is used in people with certain liver cancer risk factors to help find cancers earlier. Many experts recommend that the test be done every 6 or 12 months. But no one knows for certain how often is really best.

Who should be screened?
Screening for liver cancer is not recommended for people who are not at increased risk. At this time there are no screening tests that doctors consider to be accurate enough for screening in the general population.

People at higher risk for liver cancer may be helped by screening. Many doctors recommend testing for certain groups. This includes people with cirrhosis (from any cause), especially if the cirrhosis is so severe that the patient is on the waiting list to receive a liver transplant. Without screening, while the person is waiting for a transplant, a cancer may develop and become so advanced that it is incurable. Finding cancer early usually makes it more likely that the patient will survive longer. Early cancer will also move the person up on the transplant waiting list.

Most doctors also recommend that certain people with chronic HBV or HCV infections be screened, especially those with a family history of liver cancer. In other groups at increased risk, the benefits of screening may not be as clear. If you think you are at increased risk for liver cancer, talk to your doctor about whether screening is a good option for you.


The Link Between Hepatitis C and Liver Cancer
By Paul Hansen, M.D, director, Providence Liver Cancer Clinic, Providence Cancer Center; and Ken Flora, M.D., gastroenterologist/hepatologist with The Oregon Clinic and consulting physician to Providence Liver Cancer Clinic

I heard recently that liver cancer is on the rise. Why is that?
Primary liver cancer — cancer that starts in the liver, rather than spreading to the liver from somewhere else — is increasing rapidly right now. This increase is linked mainly to the spread of hepatitis C infection in the ’60s, ’70s and ’80s.

Hepatitis C, a virus that inflames the liver, is one of the main causes of primary liver cancer, or “hepatocellular” cancer. It wasn’t until the late 1980s that we began to understand hepatitis C and how it was spread — through blood. Until then, blood donations weren’t screened for hepatitis C, so a lot of people were exposed to the virus through transfusions, as well as other ways, such as using shared needles used to inject drugs.

Since the hepatitis C virus progresses very slowly, we’re just now starting to see complications arise among this large population that was exposed 20, 30 or 40 years ago. Liver cancer is one of the potential complications.

Does everyone with hepatitis C eventually develop liver cancer?
No — in fact, most don’t. Only people who develop cirrhosis as a complication of hepatitis C have a higher risk of developing liver cancer. About 20 percent of people with hepatitis C develop cirrhosis — advanced liver scarring caused by decades of inflammation. Of those who do develop cirrhosis, about 20 percent eventually develop liver cancer. So overall, among all people with hepatitis C, the chance of developing liver cancer at some point in your life is about 4 percent.

What makes some people with hepatitis C more or less likely to get liver cancer?
If you don’t develop cirrhosis, then you are at no higher risk of liver cancer than the general public. Having cirrhosis is what raises the risk, so anything that increases your risk of developing cirrhosis will also increase your risk of developing liver cancer.

Alcohol consumption is the key risk factor here. People with hepatitis C should not drink alcohol, since it can accelerate liver damage. Certain prescription and non-prescription drugs also can damage the liver, so people with hepatitis C should review their medications with their physician to make sure they aren’t taking anything that could put further stress on their liver. Finally, smoking increases the risk of all cancers, including liver cancer, so people with hepatitis C should not smoke.

How does hepatitis C lead to liver cancer?
Hepatitis C inflames the liver, and over the course of many years, this inflammation can lead to scarring. Most people with hepatitis C never experience significant scarring or complications, but about 20 percent develop cirrhosis, which is advanced scarring throughout the liver.

Because hepatitis C is a slowly progressive virus, it can take 30 or 40 years for cirrhosis to develop. Meanwhile, the liver is resilient — when damage occurs, the liver goes to work to regenerate itself. We believe that cancer occurs during this ongoing cycle of injury and regeneration. The more cells the liver regenerates, the higher the chances that a mutation will occur in one of those cells, and it’s these mutations that can lead to hepatocellular cancer.

Is there a way to screen people with hepatitis C to check for liver cancer?
Yes. Ultrasound is the main screening tool used to check for tumors in the liver. Ultrasound is non-invasive and can detect tumors when they are quite small.

Should everyone with hepatitis C get ultrasound screenings?
Since liver cancer is a complication of cirrhosis, people who don’t have cirrhosis don’t need to be monitored closely for liver cancer. But people who do have cirrhosis should definitely get regular ultrasound screenings to check for liver tumors.

How often should a person with cirrhosis get screened for liver cancer?
At the Providence Liver and Pancreas Clinic, we recommend that people with cirrhosis get an ultrasound screening twice a year. The more vigilant you are about getting these screenings regularly, the better your chances of catching cancer early, when treatment is most likely to be successful.

Are there any symptoms of liver cancer that a person should watch for?
Liver cancer usually doesn’t present any outward symptoms in its early stages, which is why regular screening is so important. Signs of advanced liver cancer may include pain, tenderness or a lump on the upper right side of the abdomen; enlargement of the abdomen; jaundice (yellowing of the skin and whites of the eyes); easy bruising or bleeding; nausea; fatigue; loss of appetite; unexplained weight loss; or pain around the right shoulder blade.

Can liver cancer be treated?
In many cases, yes. The treatment options generally depend on the size and the number of tumors in the liver. That’s why we say that the best treatment for liver cancer is appropriate surveillance, which means keeping your ultrasound appointments so we can catch cancer when it is most treatable.

What are the options for a person whose cancer is caught early?
If tumors are found when they are small and there aren’t many of them, we can remove them either through surgery (“resection”) or through radiofrequency ablation.

Advances in minimally invasive surgery are making it possible to perform many tumor resections through tiny half-inch incisions, rather than opening up a large incision. These “laparoscopic” techniques minimize trauma to surrounding tissues and leave patients with just two or three tiny scars.

While resection involves cutting tumors out, radiofrequency ablation involves zapping or burning tumors with localized electrical energy, which destroys the tumor and a small margin of tissue around the outside of it. This procedure can be performed laparoscopically, as well.

Both tumor resection and radiofrequency ablation have the potential to cure a patient of liver cancer.


What if a person has a large tumor, or a large number of tumors?
In this case, we can’t cut out or burn out the tumors, because a person with cirrhosis wouldn’t have enough healthy liver tissue left in reserve to tolerate it. Instead, we use interventional therapies, such as radiation and chemotherapy, to try to slow the growth or reduce the size of the tumors.

One of the most promising new interventional therapies is yttrium-90 bead implantation. This non-invasive procedure uses millions of tiny beads coated with a radioactive element — yttrium-90 — to deliver radiation directly to tumors. The beads are inject into a catheter leading to the main blood vessel that feeds the tumors. Once they reach the tumors, they stay there, blocking the blood supply that feeds tumor growth and destroying the tumor cells with radiation. The treatment is extremely effective at slowing down cancer growth, and can shrink tumors in many cases, as well. In some cases, tumors shrink so much that they become small enough for resection or ablation.

What if a patient isn’t a candidate for these therapies. Are there any other options?
The final treatment option is a liver transplant. A person whose primary tumor is less than 5 centimeters in diameter, or who has no more than three small tumors (each less than 3 cm), can get on the transplant list. However, only about 7,000 livers become available for transplant each year, and there are about 55,000 people on the waiting list in the United States. Preference is given to people who will have the best prognosis after transplantation.

What is the prognosis after a liver transplant? Even if it cures the liver cancer, doesn’t the patient still have hepatitis C?
A transplant won’t cure hepatitis C, but it will remove the cancer and the cirrhosis. Remember that hepatitis C is a slowly progressing virus, and it can take decades to lead to cirrhosis — the main risk factor for liver cancer. After a transplant, the new liver will become infected with hepatitis C, but it will take at least 10 or 15 years for cirrhosis to develop. That gives patients an extra 10 or 15 years of health and hope, during which time scientists will continue to develop more effective therapies.


National Cancer Information Center (NCIC) at 1-800-ACS-2345 can help you get answers to questions about hepatocelluar cancer and other cancer-related issues. The NCIC is open 24 hours a day, 7 days a week.

http://www.providence.org/oregon/health_resource_centers/cancer/faq.htm
http://www.cancer.org/

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