Colorectal cancer

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Chemotherapy for colorectal cancer

Chemotherapy uses anticancer, or cytotoxic, drugs to destroy cancer cells. It is sometimes used to treat colorectal cancer. Your healthcare team will consider your personal needs to plan the drugs, doses and schedules of chemotherapy. You may also receive other treatments.

Chemotherapy is given for different reasons. You may have chemotherapy to:

  • destroy cancer cells in the body
  • shrink a tumour before other treatments such as surgery or radiation therapy (called neoadjuvant chemotherapy)
  • destroy cancer cells left behind after surgery and reduce the risk of the cancer recurring (called adjuvant chemotherapy)
  • relieve pain or control the symptoms of advanced colorectal cancer (called palliative chemotherapy)

Chemotherapy is usually a systemic therapy. This means that the drugs travel through the bloodstream to reach and destroy cancer cells all over the body, including those that may have broken away from the primary tumour in the colon or rectum.

Chemotherapy drugs commonly used for colorectal cancer

The most common chemotherapy drugs used to treat colorectal cancer are:

  • 5-fluorouracil (Adrucil, 5-FU) given intravenously
  • capecitabine (Xeloda) given as a pill
  • oxaliplatin (Eloxatin) given intravenously
  • irinotecan (Camptosar) given intravenously
  • raltitrexed (Tomudex) given intravenously

The following chemotherapy combinations are used to treat colorectal cancer. Leucovorin is a drug that helps 5-fluorouracil work better.

  • 5-fluorouracil with leucovorin given every 1–4 weeks over 6 months
  • FOLFOX (leucovorin, 5-fluorouracil and oxaliplatin) given every 2 weeks for 12 cycles over 6 months
  • CAPOX (capecitabine and oxaliplatin), or XELOX, given every 3 weeks for 8 cycles over 6 months
  • FOLFIRI (leucovorin, 5-fluorouracil and irinotecan) given intravenously every 2 weeks until disease progresses
  • CAPIRI (capecitabine and irinotecan) given every 3 weeks until the disease progresses or for no more than 16 cycles

If colorectal cancer doesn’t respond to these drugs or if it recurs, you may be offered targeted therapy. Irinotecan or a chemotherapy combination with irinotecan may also be used if it wasn’t used before. Trifluridine plus tipiracil hydrochloride (Lonsurf) may be used for metastatic colorectal cancer if most other chemotherapy combinations and targeted therapies haven’t worked. This is given as a pill.


Chemoradiation is treatment that combines chemotherapy with radiation therapy. Chemotherapy is given during the same time period as radiation therapy. Some types of chemotherapy make radiation therapy more effective.

Chemoradiation is often used before surgery (called neoadjuvant therapy) for rectal cancer. 5-fluorouracil or capecitabine are the drugs usually given in chemoradiation.

Hepatic arterial infusion

Hepatic arterial infusion may be used to treat liver metastases when cancer has only spread to the liver and it can’t be removed with surgery. It delivers chemotherapy directly to liver tumours through the main artery of the liver (called the hepatic artery). Floxuridine (FUDR) is the most common chemotherapy drug used for hepatic arterial infusion.

Hepatic arterial infusion tends to have fewer side effects than systemic chemotherapy. But it is not used as often as systemic chemotherapy because it has to be done in a hospital by a large healthcare team who are trained to give this treatment.

Information about specific cancer drugs

Details on specific drugs change quite regularly. Find out more about sources of drug information and where to get details on specific drugs.

Questions to ask about chemotherapy

Find out more about chemotherapy. To make the decisions that are right for you, ask your healthcare team questions about chemotherapy.


Researcher Dr Stuart Peacock Research at the Canadian Centre for Applied Research in Cancer Control led to a new standard in leukemia testing.

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