Colorectal cancer

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Treatments for colorectal cancer

If you have colorectal cancer, your healthcare team will create a treatment plan just for you. It will be based on your needs and may include a combination of different treatments. When deciding which treatments to offer for colorectal cancer, your healthcare team will consider:

  • the location of the tumour or where the cancer has come back (recurred)
  • the stage of the cancer
  • your general health
  • your personal preferences

You may be offered one or more of the following treatments for colorectal cancer.


Surgery is the primary treatment for most colorectal cancers. Depending on the stage and location of the tumour, you may have one of the following types of surgery.

Local excision, or local resection, is mainly used to remove polyps or early stage tumours that are on the surface of the lining of the colon or rectum (called superficial tumours). The surgeon uses special equipment, usually an endoscope, to remove the polyp or tumour along with a margin of healthy tissue around it. Local excision is also done to remove a local recurrence of rectal cancer or to relieve symptoms such as pain (called palliative surgery).

Bowel resection is the most common type of surgery for colorectal cancer. It removes part of the intestine and nearby lymph nodes. Depending on the location of the tumour, the surgeon may do one of the following types of bowel resection:

  • right hemicolectomy removes the right side of the colon
  • transverse colectomy removes the middle part of the colon
  • left hemicolectomy removes the left side of the colon
  • sigmoid colectomy removes the last part of the colon
  • low anterior resection removes the last part of the colon and part of the rectum
  • proctocolectomy removes the rectum and part of the sigmoid colon (last part of the colon)
  • abdominoperineal resection removes the rectum, anal canal and surrounding muscles
  • subtotal colectomy removes most of the colon
  • total colectomy removes all of the colon

Colostomy or ileostomy may be done after a bowel resection. These surgeries may also be done to bypass or prevent a blockage in the intestine (called bowel obstruction). Colostomy creates a stoma (artificial opening) from the colon to the outside of the body through the abdominal wall. Ileostomy creates a stoma from the ileum (the last part of the small intestine) to the outside of the body through the abdominal wall. A colostomy or ileostomy can be temporary or permanent.

Pelvic exenteration may be done to treat stage 4 or recurrent rectal cancer that has spread to nearby organs. It removes the rectum, other organs in the pelvis (including the reproductive organs) and lymph nodes. Sometimes the bladder and part of the colon are removed.

Surgery to remove metastatic tumours is done when there are only one or few metastatic tumours in the liver or lungs.


Chemotherapy is a common treatment for colorectal cancer. It is often used after surgery for stage 2 and 3 colon cancer. Chemotherapy can be used as the main treatment for stage 4 or recurrent cancer in the colon or rectum that can’t be removed by surgery.

Chemotherapy drugs used alone or in combination to treat colorectal cancer include:

  • 5-fluorouracil (Adrucil, 5-FU)
  • capecitabine (Xeloda)
  • oxaliplatin (Eloxatin)
  • irinotecan (Camptosar)
  • raltitrexed (Tomudex)


Chemoradiation 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 given before surgery for stage 1, 2 or 3 rectal cancer (called neoadjuvant chemoradiation). It may also be given after surgery for rectal cancer, but this is not very common.

Radiation therapy

Radiation therapy is mainly used for cancer in the rectum. It is usually used before surgery and may be given as part of chemoradiation (chemotherapy given during the same time period as radiation therapy). It is sometimes given after surgery for stage 3 colon cancer to help prevent cancer from coming back, or recurring.

Radiation therapy to the abdomen, pelvis, bone or brain may be used as palliative therapy for advanced colorectal cancer that can’t be removed with surgery.

External beam radiation therapy is the most common type of radiation used. Brachytherapy may be used in certain cases.

Targeted therapy

Targeted therapy is used to treat stage 4 colorectal cancer that has spread to distant organs like the liver or lungs. It is usually given with chemotherapy, but it may be used alone.

Targeted therapy drugs used to treat colorectal cancer include:

  • bevacizumab (Avastin)
  • cetuximab (Erbitux)
  • panitumumab (Vectibix)
  • regorafenib (Stivarga)

Follow-up care

Follow-up after treatment is an important part of cancer care. You will need to have regular follow-up visits, especially in the first 5 years after treatment has finished. These visits allow your healthcare team to monitor your progress and recovery from treatment.

Clinical trials

Some clinical trials in Canada are open to people with colorectal cancer. Clinical trials look at new and better ways to prevent, find and treat cancer. Find out more about clinical trials.

Questions to ask about treatment

To make the decisions that are right for you, ask your healthcare team questions about treatment.

external radiation therapy

A type of radiation therapy that uses a machine outside the body to direct a beam of radiation through the skin to a specific part of the body, usually a tumour.

Also called external beam radiation therapy.


A type of internal radiation therapy that places a sealed container of radiation substance (called an implant) to deliver radiation into a tumour or near a tumour.


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