LIVER CANCER

Incidence

 
Liver cancer is very common and can be considered as two types – primary and secondary.
 

Secondary liver cancer  

 
Occurs when a cancer develops within some other organ such as the bowel, stomach, pancreas or breast and then spreads to the liver.
 
MetastasisThe liver is the most common site of metastases (deposits of cancerous cells distant from the primary source) from cancers originating in the abdominal organs and approximately one third of these cancers ultimately spread to the liver.
 
In Australia, most diagnosed cases of liver cancer are a result of spread from other primary cancer sites.
 

Primary liver cancer (hepatocellular carcinoma or HCC)

 
Cancer that arises from hepatocytes, the major cell type of the liver. 
 
Worldwide, liver cancer is either the number one or number two cause of cancer death. It is especially prevalent in parts of Asia, New Guinea, the Pacific Islands and Africa. In those countries, more than 80% of cases are due to chronic hepatitis B infection. 
 
Until recently, HCC has been uncommon in Australia and other countries with a predominantly European population. 
 
Prior to the late 1980’s, most cases of liver cancer in Australia were associated with alcoholic cirrhosis or haemochromatosis, but by 1990, hepatitis B and C were responsible for more than half the reported cases of HCC. It is predicted that the incidence of HCC will continue to rise, at least until 2020. 
 

Causes of Liver Cancer 

 
About 80% of people with HCC have cirrhosis.
 
A few liver cancers occur in an otherwise normal liver but these are fairly rare and probably account for less than 10% of cases in Australia. 
 
Some of the causes of cirrhosis and liver cancer are listed below.
 
1. Hepatitis B virus – This is the most common cause of liver cancer worldwide. There is strong evidence today that by treating the virus (and therefore the inflammation caused by the virus) the chance of progressing to cirrhosis and liver cancer should be reduced. This also applies to hepatitis C.
 
2. Hepatitis C virus – second most common cause of liver cancer worldwide. As there are approx 15,000 new hepatitis C notifications per year in Australia alone and considering the natural history of the virus, it is predicted that the incidence of HCC will continue to rise. 
 
3. Chronic excessive alcohol intake (alcoholic liver disease) – an important causal factor on its own but can add to the progression of Hepatitis B and C.
 
4. Aflatoxin – produced by a mould that is a contaminant of some nuts, grains and beans.
 
5. Iron overload (usually genetic haemochromatosis)
 

Other Risk factors

 
• Age – average age for someone to develop HCC is mid 50s. Very rare in those under 40 years of age.

• Sex – Liver cancer is 5 times more common in men than in women.

• Country of birth – in the case of hepatitis B, people are more likely to develop cirrhosis and HCC if the infection was acquired at a young age.

• Co-infection with another hepatitis virus or the HIV virus in counties where infection at or around the time of birth is common, HCC is more prevalent.
 

Diagnosis of Liver Cancer

 
Frequently, patients with liver tumours have no symptoms. Eventually however, people will develop symptoms such as pain, abdominal fullness, fever and/or jaundice.
 
Most hepatocellular carcinomas are first suspected based on the results of CAT scans or ultrasound scans.
 
A blood test called “Alpha – fetoprotein” is a useful marker for the diagnosis of HCC and about 70% of patients with liver cancer have elevated blood alpha-fetoprotein levels. Although by no means conclusive, a rising blood alpha-fetoprotein concentration (persistently over 500ug/ml) in someone with chronic liver disease suggests the development of HCC.
 

Can liver cancer be cured?

 
Treatment of secondary liver cancer varies with the underlying disease, the extent of spread in the liver and other organs. 
 
Some of the less common cancers such as testicular cancer involving the liver can be cured with combination chemotherapy. Breast carcinoma and lung cancer patients will often have a partial remission of the cancer with chemotherapy. Bowel cancer may spread solely or mainly to the liver, making treatment a viable option.
 
Surgery in some suitable cases of liver cancer can be curative. In primary liver cancer, the cure rate for small cancers by surgery is quite good (five year survival is more than 50%) but an ongoing problem is the formation of new cancers in the highly diseased, cirrhotic liver. Also, in advanced liver disease there can be many contraindications to major surgery.
 
These considerations have led to increased interest in liver transplantation to treat small liver cancers. However, there remains the difficulty of finding sufficient numbers of organ donors.
 
Conventional chemotherapy has very little to offer someone with HCC. Remissions are achieved in less than one-third of those treated and are almost always of short duration (3-9 months), while the drugs that can produce remission are very toxic.
 
Hepatocellular Carcinoma and Malignant CellsChemoembolisatiion is a specialised type of chemotherapy delivered into the branch of the hepatic artery that supplies the tumour. It represents another way to achieve local control of liver tumours by limiting the spread of HCC cells into the bloodstream. In general, chemoembolisation is reasonably well tolerated.
 
Ablation therapy is a method of treating liver cancer using a variety of techniques to shrink the tumour and slow the spread. At present, in Australia the most promising
approach is RFA or radiofrequency ablation.
 
All local therapies can potentially remove smaller tumours or shrink and temporarily control larger ones but there are limitations:
 
• Treatment may require several sessions
• Procedures performed through the skin can cause severe pain
• Formation of new tumours is almost inevitable within five years
 

Palliative care – alleviating symptoms

 
Unfortunately, only a small proportion of cases of liver cancer can be cured. In the remaining cases, symptoms are likely to occur sooner or later.
 
Pain is the most common symptom and is due to local invasion of the liver capsule and neighbouring structures hat contain pain fibres. 
 
The approach to pain control is similar to other cancers. Simple analgesics should be used first, moving to opiates as indicated and using doses and routes of administration that are appropriate to individual needs.
 
Fatigue, lethargy and weakness are the other common disabling symptoms with liver cancer. Loss of appetite is also common and may be helped by eating frequent, small carbohydrate-rich meals.
 
As well as the family doctor, the assistance of a pain clinic or palliative care team linked to a community service is invaluable to provide the best of care to someone with terminal liver cancer.
 
Acknowledgments: Hepatitis C, liver disorders and liver health – Geoffrey Farrell
Hepatocellular Carcinoma – Howard J. Worman MD – Dept gastroenterology, Columbia