Chemotherapy for colon cancer

Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. The drugs circulate throughout the body in the bloodstream.

This page is about chemotherapy for large bowel (colon) cancer that hasn’t spread to another part of the body.

You might have chemotherapy before or after surgery for colon cancer.  Common chemotherapy drugs for bowel cancer used before or after surgery are fluorouracil, capecitabine and oxaliplatin.

When you have chemotherapy

You’re likely to have chemotherapy after surgery for colon cancer if you have:

  • stage 2 cancer and your cancer has features which increase the risk of it coming back 
  • stage 3 cancer

This is to reduce the chance of the cancer coming back and is called adjuvant chemotherapy. You don’t usually need chemotherapy if you have stage 1 colon cancer.

Chemotherapy is also sometimes given before surgery for colon cancer and this is called neo-adjuvant treatment. Patients with large tumours on CT scans may benefit from having chemotherapy to shrink the cancer before surgery.

You might also have chemotherapy if your bowel cancer has spread to another part of your body (advanced bowel cancer).

How often do you have it?

You usually have chemotherapy every 2 to 3 weeks depending on what drugs you have. Each 2 to 3 week period is called a cycle. You may have up to 8 cycles of chemotherapy.

Types of chemotherapy

Usually you have a combination of 2 or 3 drugs, the most common types are:

  • capecitabine
  • fluorouracil (5FU)
  • folinic acid (leucovorin or calcium folinate), fluorouracil and oxaliplatin (FOLFOX)
  • irinotecan (Campto)
  • oxaliplatin and capecitabine

Oxaliplatin and capecitabine drug combination can also be called XELOX, CAPOX, CAPE-OX or OxCap.  

The type of drug you have depends on different factors. These include your risk of the cancer coming back and whether you have any other medical conditions.

The doctor also considers the drug side effects and will discuss this with you, so you can decide on your treatment plan together.

How you have chemotherapy

Most of the chemotherapy drugs you have for bowel cancer are given into your bloodstream (intravenously). Capecitabine is a tablet.

Into your bloodstream

You have treatment through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.

Or you might have treatment through a long line: a central line, a PICC line or a portacath. These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment.

Diagram showing a central line


You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

Whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, not more or less.

Talk to your healthcare team before you stop taking or miss a dose of a cancer drug.

Where you have chemotherapy

You usually have treatment into your bloodstream at the cancer day clinic. You might sit in a chair for a few hours so it’s a good idea to take things in to do. For example, newspapers, books or electronic devices can all help to pass the time. You can usually bring a friend or family member with you.

You have some types of chemotherapy over several days. You might be able to have some drugs through a small portable pump that you take home.

For some types of chemotherapy you have to stay in a hospital ward. This could be overnight or for a couple of days.

Some hospitals may give certain chemotherapy treatments to you at home. Your doctor or nurse can tell you more about this.

Before you start chemotherapy

You need to have blood tests to make sure it’s safe to start treatment. You usually have these a few days before or on the day you start treatment. You have blood tests before each round or cycle of treatment.

Side effects

Common chemotherapy side effects include:

  • feeling sick
  • loss of appetite
  • losing weight
  • feeling very tired
  • a lower resistance to infections
  • bleeding and bruising easily
  • diarrhoea or constipation
  • hair loss
Contact your advice line or your doctor or nurse immediately if you have signs of infection, such as a temperature above 37.5C, or if you develop a severe skin reaction. Signs of a severe skin reaction include peeling or blistering of the skin.

Side effects depend on:

  • which drugs you have
  • how much of each drug you have
  • how you react

Tell your treatment team about any side effects that you have.

Most side effects only last for a few days or so. Your treatment team can help to manage any side effects that you have.

DPD deficiency

Between 2 and 8 out of 100 people (2 to 8%) have low levels of an enzyme called dihydropyrimidine dehydrogenase (DPD) in their bodies. A lack of DPD can mean you’re more likely to have severe side effects from capecitabine or fluorouracil. It might take you a bit longer to recover from the chemotherapy. These side effects can rarely be life threatening.

Before starting treatment with capecitabine or fluorouracil you have a blood test to check levels of DPD. So you may start treatment with a lower amount (dose) of the drug or have a different treatment. Your doctor or nurse will talk to you about this.

When you go home

Chemotherapy for bowel cancer can be difficult to cope with. Tell your doctor or nurse about any problems or side effects that you have. The nurse will give you telephone numbers to call if you have any problems at home.

  • Localised colon cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.
    G Argilés and others
    Annals of Oncology, 2020. Volume 31, Issue 10 Pages 1291-1305

  • Colorectal cancer 
    The National Institute for Health and Care Excellence (NICE), 2020. Updated December 2021

  • Association of Coloproctology of Great Britain & Ireland (ACPGBI): Guidelines for the management of cancer of the colon, rectum and anus (2017) - Multidisciplinary Management
    S Gollins and others  
    Colorectal disease, 2017. Volume 19, Pages 37-66                                                                                                  

  • Colorectal cancer
    British Medical Journal (BMJ) Best Practice Online. August 2016.

  • Current opinion on optimal treatment for colorectal cancer
    T. Price and others
    Expert review of anticancer therapy 13.5 (2013): 597-611. 

Last reviewed: 
04 Feb 2022
Next review due: 
05 Feb 2025

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