If bowel cancer spreads outside the bowel to other parts of the body, the areas of spread are called metastases or secondary cancers. This advanced disease needs the experience and skills of an oncologist and other specialist doctors to tailor the best treatment pathway for you. This may involve surgery, chemotherapy and / or radiotherapy. It may possibly include targeted therapies.
Biological therapies, also known as personalised or targeted therapies, or monoclonal antibodies, are an exciting development in the treatment of advanced cancer, as it may be possible to destroy cancer cells without damaging other, healthy cells and help to reduce possible side-effects. These therapies may stop cancer cells from dividing and growing; seek out cancer cells and kill them; encourage the immune system to attack cancer cells; or alter the growth of blood vessels into the tumour.
Targeted therapies are usually given in combination with other, standard chemotherapy treatments.
Scientists now understand that bowel cancer starts when the genes (or ‘blueprint’) of individual cells in the bowel are damaged or changed in some way. Knowing the genetic type of your bowel cancer can help your oncologist select the most effective treatment for you. This may also avoid giving you treatments which are unlikely to work.
Treatment with the most appropriate targeted therapy may depend on the results of specific genetic tests, called biomarkers, on the tumour tissue. Currently the most common test looks at the RAS family of genes (KRAS and NRAS). This will confirm whether your tumour has either a normal RAS gene known as ‘wild type RAS’ or a ‘mutated RAS’ gene.
If your bowel cancer has spread to other parts of your body, then you should have a RAS test done.
Up to 50% of bowel cancer tumours tested have normal, wild type genes (in all those genes assessed) which may respond to the targeted therapies cetuximab (Erbitux) or panitumumab (Vectibix). However, patients with a mutation of other genes (for example BRAF) may only gain minimal benefit from these drugs and therefore they may not be recommended.
The other 50% of bowel cancers have a RAS mutation and patients with these gene mutations are unlikely to benefit from cetuximab or panitumumab. If this is the case, you may still benefit from drugs which work in a different way.
Gene testing gives your oncologist the information he / she needs to decide if adding a targeted therapy to your chemotherapy drugs may work for you. It does not affect the way your chemotherapy is prescribed.
How are the tests done?
The biomarker tests are done on cancer cells from the tumour or biopsy that was removed during your operation or endoscopy. Even if the test is not done immediately, samples of the cancer will have been preserved and stored in the hospital laboratory. Your medical team will arrange for the tissue sample to be tested and, once the sample has been located, the test results typically take up to 3 weeks to come back to your oncologist.
The only targeted therapies currently approved by NICE (National Institute for Health & Care Excellence) and available on the NHS for colorectal cancer are:
Cetuximab (Erbitux) is used for people with RAS wild type (normal) tumours. It is only funded as a 1st line treatment in combination with FOLFOX chemotherapy (oxaliplatin + 5FU) or FOLFIRI chemotherapy (irinotecan + 5FU).
Panitumumab (Vectibix) is also used for patients with RAS wild type (normal) tumours. It is only funded as a 1st line treatment in combination with FOLFOX chemotherapy (oxaliplatin + 5FU) or FOLFIRI chemotherapy (irinotecan + 5FU).
Cetuximab and panitumumab can only be given as a 1st line treatment option. 1st line treatment is the first treatment that you are offered, either when you are diagnosed with stage 4 (metastatic) bowel cancer or when your cancer has subsequently spread to other organs. Any chemotherapy that you initially received because you were diagnosed at Stage 2 or 3 does not count for this purpose.
You can only receive either cetuximab or panitumumab and not both during your courses of treatment. However, if on the rare occasion that a patient does not tolerate one of them (for example if they have an allergic reaction) they may sometimes be switched to the other one.
Please click here for our Treatment Options in England & Wales chart.
The antibodies cetuximab (Erbitux) and panitumumab (Vectibix) have very recently been approved by NICE and will be available in Northern Ireland through an application process to your HSC Trust and the NI Health and Social Care Board. These two drugs are available under the same rules that apply to England and Wales, as above.
Please click here for our Treatment Options in N. Ireland chart
In Scotland, the availability of drugs on the NHS is decided by the Scottish Medicines Consortium. Some drugs are put forward to the PACE system (Patient and Clinician Engagement).
The drugs cetuximab (Erbitux) and panitumumab (Vectibix) are available under the same rules that apply to England and Wales.
In addition, patients in Scotland have access to aflibercept (Zaltrap) as a 2nd line treatment option in combination with FOLIFIRI chemotherapy (irinotecan + 5FU) for patients with metastatic colorectal cancer that is resistant to or has progressed while being treated with oxaliplatin.
Please click here for our Treatment Options in Scotland chart.
Some drugs are not routinely funded. This is because NICE considers their benefits to be small and they are not cost-effective. They are however licenced and there is clinical evidence that they have a small benefit when combined with conventional chemotherapy – bevacizumab (Avastin) or aflibercept (Zaltrap)*, or as a single agent – regorafenib (Stivarga).
*available on NHS only in Scotland
Private health insurance may cover the cost of these treatments, depending on your policy.
The only way to access drugs not funded y the NHS is by the co-payment (top-up) scheme. You will have to pay for the cost of the drug and its administration but the rest of the care on the NHS is included as part of your normal care and doesn’t have to be paid for. None-the-less, the cost of these drugs can be high and can amount to thousands of pounds per month. A quote will need to be supplied by your treating hospital. Please click here for guidance for NHS patients who wish to pay for additional private care.
The only way that you can currently access any other treatment drugs free of charge is by asking your oncologist to apply for an Independent Patient Funding Request. They will need to demonstrate that you are an exceptional case and why you are more likely to benefit from a medicine than would normally be expected. Unfortunately, only a small number of these applications are successful.
We have a full explanation of clinical trials here.
You can search for clinical trials taking place in the UK through:
The Experimental Cancer Medicine Centre Network (ECMC), a network of 18 ‘virtual’ centres across the UK designed to bring new treatments to cancer patients as quickly as possible.