How can cancer involve the liver?

There are two ways in which cancer can involve the liver. The cancer can arise from the liver itself (primary liver cancer) or it can spread to the liver from a primary tumour at another site (secondary, or metastatic, cancer).

In the UK, secondary liver cancer is about 30 times more common than primary liver cancer. Each year there are about 90,000 patients in the UK with secondary liver cancer and about 3,100 with primary liver cancer.

Primary liver cancer

Primary liver cancer can arise from the liver cells themselves (hepatocellular carcinoma) or from the system of tubes that drains the bile from the liver (cholangiocarcinoma, gall bladder cancer).

Most patients with primary liver cancer have suffered previously from liver disease such as chronic hepatitis, cirrhosis or, in the less developed world, have been exposed to poisons from plants (aflatoxins).

Immunisation against hepatitis B might, particularly in the developing world, prevent many cases of primary liver cancer.

Worldwide, primary liver cancer is the third most common cause of death from cancer.

What are the symptoms of primary liver cancer?

People with chronic liver disease may develop liver cancer without noticing any new symptoms. The typical symptoms are discomfort or pain in the right side of the upper abdomen, weight loss and tiredness.

How is primary liver cancer diagnosed?

Primary liver cancer can be diagnosed using a combination of blood tests, diagnostic imaging and image-guided biopsy. The blood test that is most useful is AFP (alpha-fetoprotein).

These tumours will often show on an ultrasound scan, but for full assessment both CT and MRI scans are required.

A needle biopsy using ultrasound (or other imaging) guidance will usually confirm the diagnosis.

How is primary liver cancer treated?

Primary liver cancer is difficult to treat. Surgical removal is the best option but these tumours are often too large and too extensive for surgery.

For fit patients with limited tumours surgical removal may be possible. Liver transplant may also be an option.

Some tumours can be treated by injecting them with alcohol (PEI – percutaneous ethanol injection) or heating them with electrodes (RFA – radiofrequency ablation). This can be done by using needles passed through the skin or by using keyhole surgery.

A technique called TACE (transarterial chemoembolisation) can be used for more advanced tumours.

An interventional radiologist can place a catheter into the artery supplying the tumour and this can be used to deliver chemotherapy drugs mixed with a syrupy fluid directly to the tumour. This approach both delivers the cell-killing drug directly to the tumour and cuts off its blood supply.

Standard intravenous chemotherapy is occasionally used for inoperable tumours but any benefit is usually short lived.

Experimental treatments include biological agents such as cetuximab (eg Erbitux) and sorafenib or using catheters to deliver tiny radioactive pellets to the tumour (SIRT – selective internal radiation therapy).

Specialised techniques, involving the temporary placement of radioactive wires, can be used to treat certain primary cancers of the ducts within, or immediately adjacent to, the liver.

Unfortunately, survival rates for primary liver cancer are low – the three-year survival rate is less than five per cent.

Secondary (metastatic) liver cancer

Secondary (metastatic) cancer reaches the liver by spreading through the blood system from a primary tumour at a separate site.

In about 50 per cent of patients with metastatic liver cancer, the primary tumour is in the bowel (colon, rectum) or stomach. The other common primary sites are the breasts and lungs.

What are the symptoms of secondary cancer involving the liver?

The symptoms can include:

• tiredness
• loss of appetite
• nausea
• a dragging sensation or heaviness felt up under the lower ribs on the right-hand side of the body
• pain in the upper part of the belly, particularly on bending forwards.

In the later stages, the skin can develop a yellowish tinge (jaundice) together with fevers and drenching sweats, particularly at night.

How is secondary liver cancer diagnosed?

The diagnosis is usually made with a combination of imaging tests (ultrasound, CT scan, MRI) and image-guided biopsy. Sometimes blood tests, for example a CEA (carcinoembryonic antigen) test, in someone with a history of bowel cancer may also be useful.

How is secondary liver cancer treated?

The treatment of secondary (metastatic) liver cancer is determined by the site of origin of the original (primary) tumour.

It’s important to realise that the tumour, even though it has spread to the liver, will still behave according to its origin. A leopard does not change its spots: breast cancer involving the liver behaves like breast cancer, not like primary liver cancer. Consequently the outlook can be rather better for patients with secondary, as opposed to primary, liver cancer.

Surgery is increasingly being used for patients with secondary liver cancer. This can sometimes involve removing a segment of liver.

Alternatively, keyhole techniques can be used to apply extreme cold (cryosurgery) or heat (radiofrequency ablation – RFA) to localised areas of the liver.

Selective internal radiation therapy (SIRT) is an experimental technique that involves delivering microscopic radioactive spheres directly to the tumours via their blood supply.

The presence of secondary cancer within the liver implies that the primary tumour has spread via the bloodstream and as a result other organs may be at risk.

It is sensible, therefore, to consider using a treatment such as chemotherapy, which acts all over the body. The type of chemotherapy used will depend on the type of primary cancer.

Hormone treatment is an additional option for patients with cancers of the breast or prostate that have spread to the liver.