Primary Liver Cancer or Hepatoma
What is Liver Cancer?
The liver is one of the major organs of the body, and is crucial to live (hence the name “live-r”). It is involved in many processes of the body such as manufacturing various essential proteins, processing and storing nutrients, destroying toxins and poisons among others. The liver is made up of many different cell types but the two main ones are liver cells (hepatocytes) and cells lining the bile ducts (cholangiocytes).
Like any other part of the body, the cells in the liver can undergo changes to form cancer. Liver cells that become cancerous form liver cancer (hepatocellular carcinoma, HCC). Bile duct cells change into the cancerous cholangiocarcinoma. Cancerous cells that start from other parts of the body and spread to the liver, for example colon cancer spreading, do not constitute liver cancer in the strict sense. These are known as secondary liver tumours or metastatic cancers to the liver.
How common is Liver Cancer?
Liver cancer is the fourth commonest cancer worldwide. In Singapore it is the fourth commonest cancer among men, and the third commonest gastrointestinal tract cancer among all. It affects about 14 individuals in every 100,000 people a year.
Liver cancer is mainly an Asian disease, and is common in South-East Asia, China, Japan and Korea. It is also common in parts of Africa and the Mediterranean (especially Italy).
Age of Onset
Liver cancer presents mainly in the older age group, from 40s to 50s. It can affect a younger individual who has contracted chronic hepatitis B or C from birth or in those with certain congenital conditions.
Risks and Causes
The three main causative factors for liver cancer are hepatitis B carrier status, hepatitis C infection and alcoholic liver disease. Other rare causes include poisons (aflatoxin) from fungus growing in badly preserved food (especially grains), congenital conditions (alpha-1 anti-trypsin deficiency), and any cause of liver hardening or cirrhosis (e.g. haemachromatosis).
The risk of an individual with hepatitis B or C of getting liver cancer is 100 times increased compared to a normal person. The pattern of liver cancer worldwide follows closely with the pattern of hepatitis B and C infections. In countries where immunization for hepatitis B has been started, the number of liver cancers seen a year have also fallen in line with a fall in the number of hepatitis B cases. Hepatitis B can be transmitted from an infected mother to her baby during pregnancy. In the adult setting, hepatitis B and C can be transmitted by contact with infected body fluids, e.g. saliva, blood, sperm and other secretions. Blood transfusion is no longer a risk factor because of adequate screening methods in Singapore.
Alcohol is the main cause for liver cancer in the Western population. The liver is damaged by repeated and excessive alcohol abuse leading to liver hardening (cirrhosis) and cancer change.
Symptoms and Signs of Liver Cancer
The majority of patients with liver cancer have no symptoms. It is very often detected by chance as a result of an ultrasound test or CT scan for other unrelated problems. In some patients there may be vague symptoms of heaviness or discomfort in the right side of the abdomen. Pain and appetite or weight loss are usually late symptoms.
In a small group of patients, liver cancer presents as a sudden intense pain in the abdomen as a result of rupture of the tumour. This is usually a bad sign and is related to bleeding of the tumour inside the abdomen.
Diagnostic Tests
A simple blood test for alphafetoprotein (AFP) may detect liver cancer. Levels below 10 are normal. In up to 30% of patients with liver cancer, the AFP can be normal. Other causes of a raised AFP include early childhood, liver damage from hepatitis, or tumours of the testis. By itself, the AFP test has significance and must be interpreted together with a proper imaging study of the liver.
The simplest imaging study of the liver is an ultrasound. This has no radiation risk and can be done on a regular basis, especially in individuals who are at risk of liver cancer, e.g. hepatitis B carriers. It is however not always accurate and is dependent on the person doing the ultrasound scan.
A CT scan is a better way of detecting liver cancer and is crucial for planning for treatment. This would be the basic imaging that will be done by the liver surgeon to detect and plan treatment strategy for liver cancer. On occasions, a CT scan may not be enough or is inconclusive, and additional investigations like MRI or angiograms may be performed.
An MRI is like a CT scan but uses magnetic forces instead of radiation. The angiogram involves passing a fine tube into the blood vessel to inject chemicals that can be better seen on x-rays to detect tumours. This is not dissimilar to the angiogram used to assess blood vessels in the heart.
Treatment of Liver Cancer
Surgery is the treatment of choice for liver cancer. All other methods have not been shown to be as effective as surgery in treating liver cancer. Liver cancer is frequently associated with liver damage (cirrhosis) in the other parts of the liver due to alcohol damage or hepatitis. This makes surgery for liver cancer difficult or impossible in a large proportion of patients.
As surgery is the only effective method for treating liver cancer, it is crucial that a person with suspected liver cancer has a proper assessment of his condition by a well-trained liver surgeon to decide if the cancer can be removed. A liver surgeon is known as a hepatopancreaticobiliary or HPB surgeon. Liver surgery is currently safe and effective in treating liver cancer.
When surgery is not possible, there are other options that may help to control the tumour and attempt to prolong survival time but not “cure”. The many options available suggest that no single method is particularly effective. It is better to discuss these options with a trained liver cancer specialist who can advise you on the appropriateness of each method. Some of these options that are available at NCC include chemotherapy (systemic or local, TACE), alcohol injection, heat-destroying the tumour (radiofrequency ablation, RFA), or using radionuclear material to deliver local radiation. In addition a multitude of experimental options like hormone therapy, drug therapy and gene therapy are available on a case-by-case basis.
Prognosis of Liver Cancer
Liver cancer is the second most fatal cancer. If untreated most patients do not survive beyond 6 months. Surgery is the only method that allows for a reasonable survival beyond 5 years. With curative surgery, survival beyond 5 years of more than 40% is possible.
New tumour growth is common in liver cancer because of the underlying liver disease (i.e. hepatitis or cirrhosis). There is currently no effective means of preventing this new growth, and close follow-up after surgery is necessary to detect tumour regrowth at an early stage that can still be treated.
Screening
The risk groups for liver cancer are well defined and screening targeted at this group is aimed at trying to detect cancer at an early stage where surgery is still possible for cure. Although there are no formal recommendations, a patient with established hepatitis B or C carrier status would benefit from regular AFP estimations and ultrasound examinations. This can be done on 3 to 6 monthly intervals depending on the severity of liver damage, i.e. cirrhosis.
Prevention
Family members of patients with hepatitis B are advised to check their hepatitis B status and if not-infected and without protection, to go for immunization against hepatitis B. Children are currently advised immunization at birth for hepatitis B as part of a national programme. There is currently no immunization for hepatitis C.
As hepatitis B and C are spread by bodily fluids, there is an association with sexual promiscuity and multiple sexual partners, especially with unprotected sex or with sex workers. Intravenous drug abuse using contaminated syringes is a high risk factor for transmission of hepatitis B and C.
Frequently Asked Questions about Liver Cancer
1. I have blood relatives with liver cancer. Am I at higher risk of developing liver cancer?
Hepatitis B carriers who have blood relatives who have been diagnosed with liver cancer have a higher risk of developing liver cancer themselves. They should be evaluated and seen regularly by physicians who have a special interest in diseases of the liver.
2. I developed hepatitis after travelling to a nearby country. Will I develop liver damage?
There are many hepatitis viruses, such as hepatitus A virus, which are spread by eating contaminated food. The hepatitus A virus causes short term liver damage after which the liver will repair itself and no further damage is done. There are also many other viruses which do not specifically attack the liver but can cause mild short-term liver infection, such as the dengue virus.
3. My father had colon cancer. Now he has liver cancer. Why does he have two cancers?
It may be wise to ask your father's physician again what he or she has found in your father. When a patient has colon cancer and this colon cancer later spreads to the liver, the patient is still suffering from colon cancer and not from liver cancer. The cancer cells which are in the liver will behave like colon cancer cells. It is not a new cancer but rather an advanced stage of colon cancer.
Prevention:
Alcohol abuse can lead to liver cirrhosis and this dramatically increases cancer risk. The risk of an individual with hepatitis B or C getting liver cancer is also 100 times more than that of a normal person. As hepatitis B and C are sexually transmissible, having safe and responsible habits are important.
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