The Liver
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The liver is the largest organ
in the body and is situated in the upper abdomen, on the right side of the body. It has
many functions, including the production of bile, which is passed into the intestines, via
a tube known as the bile duct. The liver also inactivates harmful substances such as some
drugs. It is an essential organ in the conversion of food into energy and body tissue. |
Cancer of the liver
Normally, cells die and are replaced in
equal measure. If cells begin to multiply at a faster rate than they should, a growth
forms of all the unwanted cells. Sometimes these cells alter their behaviour to become a
cancer and invade the surrounding tissue. They may also spread, away from the original
site, to other organs in the body.
A cancer occurring in the liver can either
start within the liver itself (a primary cancer), or start elsewhere in the body and then
spread to the liver (a secondary cancer). The majority of cancers seen in the liver are of
a secondary type. In the United Kingdom, primary liver cancers are relatively rare.
Generally, cancers within the
liver can be very difficult to cure.
However, clinicians and scientists are finding more ways in which both primary and
secondary cancers may be treated.
Primary Liver Cancers
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The liver is a complex organ
consisting of very many different types of cells. However, only the two principal cell
types tend to form cancers. The cells, which perform the fundamental tasks of the liver,
are called hepatocytes; the cancers these form are called hepatomas. The cells
lining the bile ducts of the liver can also change into cancers; these are termed cholangiocarcinomas.
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Hepatomas almost always occur in the livers of people who
have conditions which have damaged the liver over a long period of time. This damage
causes scarring of the liver, known as cirrhosis. Any disease that causes cirrhosis of the
liver can lead to a hepatoma. Fortunately, only a small number of people with cirrhosis
actually get a hepatoma. Certain causes of cirrhosis have a higher chance of developing
hepatomas. These are the viral infections Hepatitis B and Hepatitis C, the cirrhosis
linked to excessive alcohol, and the cirrhosis of haemochromatosis, (an uncommon condition
whereby an abnormal amount of iron is stored in liver cells).
Currently we do not understand why cholangio carcinomas
develop. So, in most people there is no obvious reason why the cancer should form. It does
occur more frequently in people who suffer a rare condition called sclerosing cholangitis,
which causes slow and progressive damage to the bile ducts.
Secondary Liver Cancers
Nearly any cancer in the body can spread to the liver.
Cancers more likely to have secondary growths in the liver are those from the stomach,
pancreas and large bowel (colon). This is because the blood stream away from these
digestive organs flows directly to the liver. Hence, all cancer cells that break away from
the original growth are carried to the liver where they can embed and grow. Breast and
lung cancers are relatively common cancers in the UK and these can also form secondary
growths within the liver.
What symptoms does a liver cancer
cause?
Early on in their growth liver cancers
often produce no symptoms. Secondary cancers tend to be found only after the original
cancer, elsewhere in the body, is diagnosed. A liver cancer may produce jaundice (a yellow
colouring of the skin and eyes), often with a darkening of urine and a pale colour to the
stool (bowel motion). This is because the growth of the cancer blocks the drainage of bile
from the liver and the bile’s yellow pigment cannot get into the bowel to colour the
stool. It then has to be got rid of through the kidneys, hence the dark urine.
Other symptoms which may occur are pain
over the liver, especially if the cancer is stretching the fibrous coating that surrounds
the liver, and weight loss. Very occasionally a liver cancer causes vomiting. This is
because the cancer grows out from the liver and pushes on the stomach, blocking the
passage of food and liquids.
How are liver
cancers diagnosed?
Apart from hepatomas, there are no
specific blood tests for the detection of liver cancer. However, a cancer in the liver
might be suspected when an abnormality is seen in ‘liver blood tests’. These
blood tests merely detect that there is something wrong and an abnormality can show up for
many other reasons besides cancer. In the case of hepatomas, a doctor may find an
unusually high concentration of a substance produced by the hepatoma, called
alpha-fetoprotein. However, this blood test is only an indication of the presence of a
hepatoma and will not detect other cancers.
The best method of diagnosing a cancer, is
being able to see it. This can be done using ultrasound, a CT scan X-ray or Magnetic
Resonance Imaging (MRI). Sometimes it is necessary to have pictures of the blood supply to
the cancer, in which case an angiogram is performed. This entails putting X-ray dye into
the blood vessels that supply the liver via a fine tube inserted into an artery, normally
at the top of the leg. Though a liver cancer may have been seen, specialists need to know
what type of cell is forming the cancer. This means that a sample of the cancer is
required. This involves introducing a needle into the cancer and then taking a small
sample (biopsy), which is examined under a microscope.
How are liver
cancers treated?
Treatment depends on (a) the type of liver
cancer and (b) the amount of the liver affected by the cancer.
Secondary liver cancers
When cancer of the colon or rectum
(bowel cancer) is diagnosed, the doctor or surgeon will frequently check to see if the
cancer has spread to the liver. If a secondary cancer is found it may be possible to
operate to remove it. The removal of not only the original bowel cancer, but also the
secondary liver growth means a cure is possible.
Most other types of secondary cancers in
the liver are difficult to remove through surgery. These are usually treated with
chemotherapy (drugs) in order to slow down the growth of cancer cells.
Primary liver cancers
Hepatomas
Since most hepatomas start in people
who have cirrhosis, doctors will regularly screen such patients in order to detect the
occurrence of a hepatoma as soon as possible. This screening may involve regular
ultrasound scans and blood testing for alpha-fetoprotein (as mentioned above). A number of
treat ments are available. Firstly, if the cancer is small and the liver cirrhosis is not
too severe, the part of the liver containing the cancer may be removed by an operation. If
the cancer is small but the cirrhosis has severely affected the liver, then occasionally a
liver transplant may be considered; however, this is a major operation, not without risk.
Also, there are many other factors that are taken into account before considering liver
transplantation. Other means of treating hepatomas include injecting substances directly
into the cancer to attempt to kill the cancer cells, or injecting materials into the blood
supply to the cancer. This stops blood getting to the cancer cells, which should kill
them, or slow their growth.
Cholangiocarcinomas
This type of primary liver cancer is
very difficult to cure. The bile duct cells that have turned into a cancer often grow and
block the main bile duct draining the liver. A blocked bile duct will cause jaundice. By
inserting a tube (called a stent) through the blockage, the jaundice can be relieved. The
size and position of the cancer can then be assessed with a view to the possibility of
having an operation.
Are liver cancers preventable?
With secondary cancers, it is important to try to prevent
the original cancer from starting. Stopping smoking greatly reduces the risk of developing
lung cancer and possibly stomach cancer. Eating more fresh fruit and vegetables reduces
the chance of suffering from colon cancer. Reducing alcohol intake to within the
recommended limits (21 units per week for a woman, and 28 units for a man), will reduce
the chance of liver cirrhosis and hence hepatomas arising.
What does the future hold?
Many liver cancers are currently very difficult to cure. A
lot of research is being done on new ways to attack cancer cells that are growing in the
liver. These ways include the development of new drug therapies, different surgical
operations and even attempts to alter the DNA code within the individual cells in order to
stop them growing. Another area of study is researching how and why these cancers start.
Summary points
 Liver cancers can be primary or secondary
A
cancer in the liver may be found when the original cancer is diagnosed (secondary
cancers), or during screening tests
Symptoms
include jaundice or upper abdominal pain
Some
types of both primary and secondary cancers can be cured with an operation
There
are other treatments for liver cancers which, though they do not cure the cancer, can slow
down the cancer growth.
FURTHER INFORMATION:
CancerBACUP is a national charity providing information
and counselling for people with cancer, their families and friends. Its Cancer Support
Service is staffed by specialists cancer nurses and professional counsellors.
CancerBACUP publishes 51 booklets on specific cancers and
practical guides on living with cancer.
CancerBACUP’s services:
Information:
Information:
- 0800
181199
Counselling: - 0171 698 9000 (London) 0141 553 1553
(Glasgow)
Publications: - 0171 696 9003
or by writing to: - Cancer BACUP, 3 Bath Place, Rivington
Street, London EC2A 3JR
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