Tests for liver cancer

Blood tests

Measuring the levels of the protein alpha-fetoprotein (AFP) in serum is the only blood test which can be used towards diagnosing HCC. Unfortunately, only about half of all tumours will give a raised reading of AFP. So a normal AFP test does not exclude the presence of HCC. This is further complicated by the fact that AFP is also produced by proliferating liver cells so somebody with cirrhosis and liver regeneration is likely to have raised AFP levels already. 

As a consequence, doctors will probably want to monitor whether AFP levels are stable or not. Rising levels of AFP are more likely to indicate HCC.

Even when there is no evidence of HCC, people with cirrhosis and an abnormal AFP still have a high risk of developing it. Anybody with cirrhosis and an elevated AFP, particularly with steadily rising AFP levels, will most likely either develop HCC or already have an undiscovered HCC.

Ultrasound

Ultrasound is usually the first screening test carried out if HCC is suspected. 

The accuracy of an ultrasound depends on the technician who performs the scan. Some experienced operators may be able to detect lesions (areas of abnormal tissue) as small as 0.5cm whereas other may only be able to identify larger lesions.

An ultrasound has the advantage of not involving ionising radiation and intravenous contrast material (injecting a chemical into the body to improve the contrast of the imaging). 

Computerised Tomography (CT) scans

When performed with an enhancing contrast agent, CT scans can be just as sensitive as ultrasound. This is because the agent improves the imaging of the arterial and venous systems.

CT scans depend much less on the skill of the operator than ultrasound. They also have the advantage of being able to provide images of more areas of the body. 

Hepatic Angiography

In this procedure a catheter is inserted into the hepatic artery and intravenous contrast material is injected into the liver.

It may be useful for studying difficult lesions but it also involves ionising radiation risks, arterial puncture and the use of contrast agent.

Hepatic angiography is usually carried out on people who are considered to be at high risk but who have not shown any signs of HCC with other imaging studies. 

At the time of angiography, if a tumour is detected, it may be decided to block the artery feeding the tumour before injecting anticancer drugs into it.

Magnetic Resonance Imaging (MRI)

Like a CT scan, an MRI can examine large areas of the chest and abdomen in a single session. However, because no ionising radiation is involved, the imaging can be repeated many times with little risk. 

Newer MRI machine can reconstruct images of the bile ducts, the gallbladder and of the arteria and veins of the liver. 

Liver biopsy

The only clear way to tell the difference between a malignant or benign growth is to examine it by removing a sample of tissue and reviewing it under a microscope. This process is called biopsy. 

A biopsy may be carried out at the same time as an ultrasound or CT scan.

Laparoscopy

In this procedure, a surgeon places an instrument called a laparoscope (a thin, flexible tube with a camera and light at the tip) into the body via a small cut in the abdomen. 

The laparoscope allows the surgeon to look directly at the liver to assess for signs of HCC.