Colorectal cancer

You are here: 

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 health and specific information about the cancer. 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
  • what you prefer or want

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.

A local excision (local resection) is surgery to remove abnormal tissue, such as a polyp or tumour, along with a margin of healthy tissue around it. It is usually used to remove stage 0 colorectal tumours, some stage 1 rectal tumours and local recurrence of rectal cancer. Types of local excisions are a polypectomy, a local transanal excision and transanal endoscopic microsurgery (TEM).

A 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, one of the following types of bowel resection will be done:

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

A 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 a bowel obstruction). A stoma (artificial opening) is created from the colon or the ileum to the outside of the body through the abdominal wall. A colostomy or ileostomy can be temporary or permanent.

A lymph node dissection is surgery to remove lymph nodes near the tumour and is done during a bowel resection.

A pelvic exenteration may be done to treat stage 4 or recurrent rectal cancer that has spread to nearby organs. The reproductive organs and lymph nodes in the pelvis are removed. Part of the colon, the rectum or both are usually removed. The bladder may also be removed.

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


Chemotherapy is sometimes used to treat colorectal cancer. 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)
  • trifluridine and tipiracil (Lonsurf)

Leucovorin (folinic acid) is a common drug used in treating colorectal cancer. It is not a chemotherapy drug but it helps 5-fluorouracil work better.


Chemotherapy is often combined with radiation therapy to treat rectal cancer. This is called chemoradiation. The 2 treatments are given during the same time period. The chemotherapy drugs that are usually given for chemoradiation are 5-fluorouracil or capecitabine.

Radiation therapy

Radiation therapy is mainly used for cancer in the rectum. It may be given alone or combined with chemotherapy as part of chemoradiation.

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

Targeted therapy

Targeted therapy is sometimes used to treat advanced colorectal cancer. It is usually given with chemotherapy, but it may be used alone.

Targeted therapy drugs used to treat colorectal cancer include:

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

If you can’t have or don’t want cancer treatment

You may want to consider a type of care to make you feel better without treating the cancer itself. This may be because the cancer treatments don’t work anymore, they’re not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can’t have or don’t want cancer treatment.

Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.

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

Talk to your doctor about clinical trials open to people with colorectal cancer in Canada. Clinical trials look at new 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.


The last part of the small intestine that receives almost completely digested food from the jejunum, absorbs more nutrients and fat, then passes digested food to the large intestine.  

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.