Biological therapies for bowel cancer

Biological therapies are drugs that can help the body to control the growth of cancer cells. Some biological therapies known as monoclonal antibodies can be used to treat colon or rectal cancer that has spread to other parts of the body.

A biological therapy called cetuximab (Erbitux) is licensed in the UK for advanced bowel cancer. We know from research that it can help some people with advanced bowel cancer to live longer when they have it with standard chemotherapy treatment. It can also improve their quality of life. You usually have cetuximab with the chemotherapy drugs 5FU (fluorouracil), oxaliplatin, or irinotecan. Doctors mainly use it when bowel cancer has spread only to the liver.

Cetuximab (Erbitux) is a type of monoclonal antibody. Some bowel cancer cells have receptors for a protein produced in the body called epidermal growth factor. This protein attaches to receptors on cancer cells and triggers them to grow. Cetuximab blocks epidermal growth factor (EGF). So it is called a growth factor blocker.

We know from recent research that between 3 and 4 out of every 10 advanced bowel cancers (35 to 40%) have a change or 'mutation' in a gene called k-ras. Cetuximab doesn't work for bowel cancers that have a k-ras mutation. So doctors can only use cetuximab to treat people whose cancer has a normal k-ras gene. If your doctor thinks that cetuximab could be a helpful treatment for you they will test your cancer cells first to see if they have a k-ras mutation.

For some people, cetuximab and chemotherapy may be able to shrink liver tumours so that they can be removed with surgery. In this situation you usually have cetuximab with FOLFOX or FOLFIRI chemotherapy. The treatment is for up to 16 weeks. Once you have finished the treatment, your doctors will check whether it will be possible to remove the cancer in your liver.

NICE have recommended that cetuximab should be available to have with chemotherapy for people with newly diagnosed bowel cancer that has spread to the liver and are fit enough for surgery. NICE has not recommended it as a treatment if you have already had chemotherapy that is no longer working because they say it is not cost effective.

The monoclonal antibodies bevacizumab (Avastin) and panitumumab (Vectibix) are licensed for advanced bowel cancer. 

NICE has said that bevacizumab and panitumumab should not be available as a treatment within the NHS for people with advanced bowel cancer. They made this recommendation because they said that they did not give enough benefit to patients for its very high cost. The Scottish Medicines Consortium (SMC) could not recommend panitumumab as a treatment within the NHS in Scotland because the pharmaceutical company making it did not put any evidence in for the SMC to review.  

There is information about these treatments in the bowel cancer research section.

Some biological therapies are very new and it will be some time before we know how well they work. All new treatments have to go through the clinical trials process and this takes some years. Research is looking into using biological therapies alongside chemotherapy to see how they work best together.

To search for bowel cancer trials, visit our clinical trials database and select 'bowel' from the drop down menu of cancer types.

The most common side effects of biological therapies for bowel cancer are

• Diarrhoea
• Weakness
• A sore mouth
• Loss of appetite
• Low blood counts
• Tiredness (fatigue)
• Swelling of parts of the body due to build up of fluid
• Skin changes such as rashes or a colour change – rashes may be severe for some people

Tell your doctor if you have any of these effects as you can have medicines to help to control them. There is information about the side effects of cancer drugs in our cancer drug section.