Treatment for metastatic bowel cancer
You might have targeted or immunotherapy drugs as part of your treatment for metastatic bowel (colorectal) cancer.
Metastatic bowel cancer is cancer:
that started in either the back passage (rectum) or large bowel (colon), and
has spread to another part of the body
It is also called advanced bowel cancer.
Targeted cancer drugs work by targeting the differences between cancer cells and normal cells that help them to grow and survive. Other drugs help the immune system attack cancer. They are called immunotherapies.
Some drugs work in more than one way.
The aim of these treatments for metastatic bowel cancer is to shrink the cancer or slow its growth. Unfortunately, they can't usually cure the cancer.
Whether you have targeted therapy or immunotherapy depends on:
changes in the cancer cells
how far the cancer has grown (the stage)
other treatments you've already had
You might need to have a test using some of your cancer cells to find out whether the treatment is likely to work. These tests look for changes in certain proteins or genes.
Your doctor usually tests a sample of your bowel cancer tissue from when you were first diagnosed. Or they may use a sample from your operation if you had one. The results will show whether a drug is suitable for you.
Your doctor can tell you if this applies to your treatment. This is not the case for all targeted and immunotherapy drugs, and you don’t always need this test.
Cetuximab (Erbitux), panitumumab (Vectibix) and bevacizumab (Avastin)
Cetuximab, panitumumab and bevacizumab are types of monoclonal antibodies. Monoclonal antibodies work by recognising and finding specific proteins. Different types of cancer have different proteins. Monoclonal antibodies stop particular proteins from binding to cancer cells. Or they block the proteins from triggering the cancer cells to divide and grow.
Cetuximab (Erbitux) and panitumumab (Vectibix) work by blocking proteins on cancer cells. These proteins are called epidermal growth factor receptors (EGFR).
A cancer needs a good blood supply to survive and grow. Bevacizumab (Avastin) stops the growth of new blood vessels caused by cancer cells. Drugs that interfere with this blood supply are called anti angiogenesis drugs.
You might have these drugs during or after chemotherapy.
Read more about monoclonal antibodies
Aflibercept (Zaltrap)
Aflibercept (Zaltrap) is also an anti angiogenesis drug. So it stops the growth of new blood vessels by the cancer cells.
Read more about drugs that block cancer blood vessel growth (anti angiogenics)
Regorafenib (Stivarga) and encorafenib (Braftovi)
Regorafenib and encorafenib are cancer growth blockers. They work by blocking particular proteins on cancer cells that help cancer to grow. Regorafenib also stops cancer from growing blood vessels.
Fruquintinib (Fruzquala)
Fruquintinib is a type of cancer growth blocker called a .
Pembrolizumab is a type of immunotherapy. It stimulates the body's immune system to fight cancer cells.
Pembrolizumab targets and blocks a protein called PD-1 on the surface of certain immune cells. These immune cells are called T-cells. Blocking PD-1 triggers the T-cells to find and kill cancer cells.
Nivolumab and ipilimumab work by blocking proteins that stop the immune system from working properly and attacking cancer cells. They help to make your immune system find and kill cancer cells.
New cancer drugs are licensed for use in a particular way. For example, a drug might have a license to treat a particular stage or type of cancer.
Once a drug has a license, several independent organisations approve the new cancer drugs. Only then can doctors prescribe them on the NHS.
Find out how NICE and the SMC makes decisions and how to access treatment in the UK
Cetuximab and panitumumab are available on the NHS for metastatic bowel cancer. You can have either of these drugs as your first treatment, in combination with chemotherapy.
You might have cetuximab and panitumumab if your bowel cancer cells have normal RAS genes and do not have the most common BRAF gene change. Normal RAS genes are also called RAS wild type.
You might have bevacizumab (Avastin) with trifluridine and tipiracil (Lonsurf) as your third treatment for metastatic bowel cancer.
You may have fruquintinib if you can’t have bevacizumab with trifluridine and tipiracil as your third treatment for metastatic bowel cancer.
Fruquintinib is only available on the NHS in England at the moment.
Aflibercept has been licensed to treat metastatic bowel cancer. But it has not been approved by NICE. So it isn’t routinely available on the NHS in England, Wales or Northern Ireland.
Aflibercept is available in Scotland. The SMC has recommended aflibercept for metastatic bowel cancer:
together with irinotecan and 5FU chemotherapy (FOLIFIRI)
as your second treatment for metastatic bowel cancer. This is in situations where your first treatment, which included oxaliplatin chemotherapy, is no longer working
Encorafenib and cetuximab are approved as a treatment in the UK if:
your bowel cancer has a BRAF V600E mutation, and
you have already had a treatment that reaches the whole body (systemic treatment), such as chemotherapy
Regorafenib is approved as a treatment for metastatic bowel cancer in the UK.
You might have it if you have already had previous treatment such as chemotherapy. Or if other treatments are not suitable for you.
Pembrolizumab is available in the UK as a treatment on the NHS for metastatic bowel cancer. It is for people whose cancer has gene changes that mean it is called:
(MMRd)
high (MSI high)
You can have this drug for up to 2 years if there are no signs of your cancer growing.
Nivolumab and ipilimumab are available as a first treatment on the NHS for bowel cancer that either:
can’t be removed with surgery
has spread
It is also an option for people with bowel cancer that has spread if they have had certain treatments before.
It is only for people whose cancer has gene changes that mean it is called:
You can have this treatment for up to 2 years if there are no signs of your cancer growing.
You have your treatment as tablets or capsules, or through a tube into your bloodstream. This depends on the type of drug you have.
You should take the right dose, not more or less.
Talk to your healthcare team before you stop taking a cancer drug, or if you have missed a dose.
You have some of these drugs through a tube into your bloodstream. A nurse puts a small tube into a vein in your hand or arm and connects the drip to it.
Or you might have a central line. This is a long plastic tube that gives the drug into a large vein, either in your chest or through a vein in your arm. It stays in while you’re having treatment.
Targeted therapy drugs and immunotherapy drugs can cause different side effects. Some of these can be serious.
Your doctor or nurse will talk to you about this. Always tell them about any side effects you have and follow the advice they give you.
Choose a drug on our A to Z list to read about side effects and find out more about the drug.
Researchers are looking at:
new targeted and immunotherapy drugs
different combinations of these drugs with other treatments
Last reviewed: 09 May 2025
Next review due: 09 May 2028
Metastatic bowel cancer is cancer that has spread from the back passage (rectum) and large intestines (colon) to other parts of the body, such as the liver. It is also called advanced cancer. Treatment includes chemotherapy, surgery, targeted cancer drugs and radiotherapy.
Deciding about treatment can be difficult when you have cancer that has spread. Treatments such as chemotherapy, targeted and immunotherapy drugs and radiotherapy can help to reduce symptoms.
Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. You might have chemotherapy for bowel cancer that has spread.
If you have metastatic bowel cancer there is information and support available to you, your family and friends.
Bowel cancer means cancer that starts in the colon (large bowel) or back passage (rectum). It is also known as colorectal cancer.
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