The liver is the largest organ in the body, and the main heatproducing organ. It is surrounded by a fibrous capsule and is divided into sections called lobes. It is situated in the upper part of the abdomen on the right-hand side of the body and is surrounded and protected from injury by the lower ribs.
The liver is connected to the small intestine (duodenum) by a tube called the bile duct. This duct takes the bile produced by the liver to the intestine.The liver has an amazing ability to repair itself. It can function normally with only a small part of it in working order.
Primary liver cancer which starts in the liver itself, is one of the most common cancers in some parts of Asia, including the coastal area of China, for example Hong Kong, Taiwan, Guangxi and Vietnam.
Two types of primary liver cancer:
-Hepatoma or Hepatocellular Carcinoma (HCC): is the most common kind and arises from the main cells of the liver (the hepatocytes).
This type is usually confined to the liver, although occasionally it spreads to other organs and occurs mostly in people with a liver disease called cirrhosis. There is also a rarer sub-type of hepatoma called Fibrolamellar hepatoma, which may occur in younger people and is not related to previous liver disease.
-Cholangio carcinoma or bile duct cancer: starts in the cells lining the bile ducts.
Some primary tumours in the liver are non-cancerous (benign) and do not spread to other parts of the body. They are usually small and may cause no symptoms, and are often discovered by chance during operations or investigations for other conditions. Unless they are causing symptoms they do not usually need to be removed.
The causes of primary liver cancer
1. Hepatoma (cancer of the liver cells):
a. Lots of people who develop hepatoma usually have a condition called cirrhosis of the liver. This is a fine scarring throughout the liver which is due to a variety of causes including infection and heavy alcohol drinking over a long period of time. However, only a small proportion of people who have cirrhosis of the liver develop primary liver cancer.
b. Infection with either the hepatitis B or hepatitis C virus can lead to liver cancer, and can also be the cause of cirrhosis, which increases the risk of developing hepatoma.
c. People who have a rare condition called haemochromatosis, which causes excess deposits of iron in the body, have a higher chance of developing hepatoma.
d. In Asia a poison called aflatoxin, found in mouldy peanuts and grain, is an important cause of hepatoma.
2. Bile duct cancers (cholangio carcinomas) are less common than hepatomas. The cause of most bile duct cancers is unknown, but they are slightly more likely to occur in people:
a. With conditions which cause inflammation of the bowel, such as ulcerative colitis.
b. In Asia, infection with a parasite known as the liver fluke is thought to cause many cholangiocarcinomas.
The symptoms of primary liver cancer
In the early stages of primary liver cancer, there are often no symptoms.
People sometimes notice a vague discomfort in the upper abdomen that may become painful. This is due to enlargement of the liver.
Pain can sometimes also be felt in the right shoulder. This
is known as referred pain and is due to an enlarged liver
stimulating the nerves beneath the diaphragm (the sheet of uscle under the lungs) which are connected to nerves in the right shoulder.
1. Common symptoms:
a. Loss of appetite
b. Weight loss
c. Feeling sick (nausea)
e. tiredness (lethargy)
f. it may also develop a high
temperature and feel shivery.
2. Other symptoms:
– The itching may sometimes be relieved by antihistamine tablets or other drugs which your doctor can prescribe. Sometimes the jaundice itself can be relieved.
– This is done by inserting a narrow tube called a stent into the bile duct to keep it open and allow the bile to flow normally into the small intestine.
– Other signs of jaundice are dark-coloured urine and pale stools (bowel motions).
Sometimes fluid builds up in the abdomen and causes swelling known as ascites. There may be several possible reasons for this:
– if cancer cells have spread to the lining of the abdomen, they can irritate it and cause fluid to build up
– if the liver itself is affected by cancer cells, this causes an increase in pressure in the veins which lead into the liver. Fluid from the abdomen cannot then pass quickly enough through the liver, so it starts to collect in the abdomen
– if the liver is damaged, it may produce less blood protein.. This may upset the body’s fluid balance, which causes fluid to build up in the body tissues, including the abdomen
– if the cancer cells blocking the lymphatic system. The lymphatic system is a network of fine channels which runs throughout the body. One of its functions is to drain off excess fluid, which is eventually passed out of the body in the urine. If some of these channels are blocked, the system cannot drain efficiently and fluid may build up.
– if ascites does develop, a tube can be put through the wall of the abdomen to drain the fluid away. Whatever the cause, jaundice or ascites will always indicate a condition that needs medical attention and so should not be ignored. Always have these symptoms checked by your doctor.
Secondary or metastatic liver cancer
This is a cancer which has started somewhere else in the body and has spread to the liver. Almost any cancer can spread to the liver, but the most common ones include bowel, pancreas, stomach, lung and breast cancer
The causes of secondary liver cancer
The cause of secondary liver cancer is always a primary cancer situated elsewhere in the body that has spread to the liver. If cancer cells from the primary cancer have escaped into the bloodstream, the liver is a likely place for them to settle as all the blood in the body passes through the liver.
The symptoms of secondary liver cancer
The symptoms are similar for both primary and secondary liver cancer. In the early stages of both these types of liver cancer there are often no symptoms. Although you should always have these symptoms checked by your doctor, it is important to remember that they are common to many conditions other than cancer.
Whatever the cause, jaundice or ascites will always indicate a condition that needs medical attention and so should not be ignored.
Article funded through the Asian Health Initiative of Tufts Medical Center
This post is also available in: Chinese