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Colorectal cancer

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Surgery for colorectal cancer

Most people with colorectal cancer will have surgery. The type of surgery you have depends mainly on the location of the tumour and how much of the colon, rectum or both needs to be removed.

Surgery is done for different reasons. You may have surgery to:

  • completely remove the tumour and nearby lymph nodes
  • completely remove cancer that has spread to other parts of the body, such as the pelvis, liver or lung
  • remove as much of the tumour as possible (called debulking) before other treatments
  • ease pain or other symptoms (called palliative treatment)

The following types of surgery are used to treat colorectal cancer. You may also have other treatments before or after surgery.

Local excision

Local excision is sometimes called local resection. It is surgery to remove abnormal tissue, such as a polyp or tumour, along with a margin of healthy tissue around it.

Local excision can be used to remove polyps or early stage tumours that are on the surface of the lining of the colon or rectum (called superficial tumours). This usually includes stage 0 tumours and some stage I tumours. Sometimes more surgery is needed to remove any cancer left behind or if cancer cells are found in the tissues removed with the tumour (called positive surgical margins).

Doctors usually use special equipment, such as an endoscope, to do local excision for colorectal cancer. The following types of local excision may be done.

Polypectomy is surgery to remove polyps. It is done during a colonoscopy or sigmoidoscopy.

Local transanal excision is used to remove stage 0 tumours in the rectum. It can also be used for some stage I rectal tumours that are small and close to the anus. The surgeon uses special tools placed in the anus.

Transanal endoscopic microsurgery (TEM) is used to remove tumours in the rectum and nearby tissue. The surgeon uses a special light and tiny tools passed through a proctoscope placed in the anus. TEM can be done for stage I tumours that are higher in the rectum.

Find out more about colonoscopy and sigmoidoscopy.

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Bowel resection

Bowel resection is surgery to remove part of the small intestine, large intestine or both. The large intestine includes the colon, rectum and anus.

Different types of bowel resection are done to remove different parts of the intestines. Each type of bowel resection is named based on what it removes. Find out more about bowel resection.

Right hemicolectomy

A right hemicolectomy removes:

  • part of the ileum (the last part of the small intestine)
  • the cecum (the first part of the large intestine)
  • the ascending colon (the first part of the colon)
  • the hepatic flexure (the bend in the colon near the liver)
  • the first part of the transverse colon (the middle of the colon)
  • the appendix

After removing these structures, the surgeon then joins the small intestine to the remaining colon. The procedure used to join them is called anastomosis.

A right hemicolectomy is used to remove tumours in the right colon, including the cecum and ascending colon. An extended right hemicolectomy, which also removes all of the transverse colon, may be done to remove tumours in the hepatic flexure or transverse colon.

Diagram of right hemicolectomy

Transverse colectomy

A transverse colectomy removes the transverse colon. The surgeon then joins the ends of the remaining colon together. The procedure used to join them is called anastomosis.

This surgery may be used to remove a tumour in the middle of the transverse colon when the cancer hasn’t spread to any other parts of the colon. Some doctors prefer to do an extended right hemicolectomy rather than a transverse colectomy.

Diagram of transverse colectomy

Left hemicolectomy

A left hemicolectomy removes:

  • part of the transverse colon
  • the splenic flexure (the bend in the colon near the spleen)
  • the descending colon
  • part of the sigmoid colon

After removing these structures, the surgeon then joins the 2 ends of the colon. The procedure used to join them is called anastomosis.

A left hemicolectomy is used to remove tumours in the left colon, including the splenic flexure.

Diagram of left hemicolectomy

Sigmoid colectomy

A sigmoid colectomy removes the sigmoid colon. The surgeon then joins the descending colon to the rectum. The procedure used to join them is called anastomosis.

Sigmoid colectomy is used to remove tumours in the sigmoid colon.

Diagram of sigmoid colectomy

Low anterior resection

A low anterior resection removes the sigmoid colon and part of the rectum. The surgeon then joins the remaining colon to the remaining rectum (called the rectal stump). The procedure used to join them is called anastomosis.

Low anterior resection is used to remove tumours in the middle or upper part of the rectum.

Diagram of low anterior resection

Proctocolectomy with coloanal anastomosis

Proctocolectomy (also called proctectomy) removes all of the rectum and part of the sigmoid colon. Coloanal anastomosis is a procedure the surgeon does to join the remaining colon to the anus.

This surgery is used to remove tumours in the lower part of the rectum. It is not used very often because many surgeons prefer to use a low anterior resection or abdominoperineal resection to remove rectal tumours.

Diagram of proctocolectomy with coloanal anastomosis

Abdominoperineal resection

An abdominoperineal resection removes the rectum, anus, anal sphincter and muscles around the anus. The surgeon makes one incision, or cut, in the abdomen and another one in the perineum (the area between the anus and vulva in women or between the anus and scrotum in men). A permanent colostomy is needed because the anal sphincter is removed.

An abdominoperineal resection is used to remove tumours that are close to the anus or have grown into muscles around the anus.

Diagram of abdominoperineal resection

Subtotal or total colectomy

Colectomy is surgery to remove part or all of the colon. If most of the colon is removed, it is called a subtotal, or partial, colectomy. If all of the colon is removed, including the cecum and the appendix, it is called a total colectomy. If the rectum is also removed along with part or all of the colon, the surgery is called a proctocolectomy.

A subtotal or total colectomy is done when there is cancer on both the right and left sides of the colon. These surgeries may also be offered to some people with familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC) as a way to prevent colorectal cancer (called prophylactic colectomy). People with an inflammatory bowel disease (IBD) may have subtotal or total colectomy to remove the damaged or diseased colon.

Depending on the type of colectomy done, the surgeon may also need to do a colostomy or ileostomy.

Diagram of total colectomy

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Lymph node dissection

Lymph node dissection, or lymphadenectomy, is surgery to remove lymph nodes. It is always done during a bowel resection. At least 12 lymph nodes near the tumour are removed. They are examined to find out if cancer has spread to them.

Total mesorectal excision (TME) is a type of lymph node dissection that removes the mesorectum, which is fat around the rectum that contains lymph nodes and blood vessels. TME is usually done during a low anterior resection or abdominoperineal resection to remove a tumour in the rectum. This surgery allows the surgeon to remove lymph nodes as well as a margin of tissue around the tumour (called the surgical margin).

Diagram of total mesorectal excision

Find out more about lymph node dissection.

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Pelvic exenteration

Pelvic exenteration is a major surgery that removes the reproductive organs along with lymph nodes in the pelvis. For colorectal cancers, part of the colon, the rectum or both are usually removed. The bladder may also be removed.

After pelvic exenteration, the surgeon may need to do a colostomy and urinary diversion. A colostomy creates an opening so that stool can pass out of the body through the abdominal wall. A urinary diversion, or urostomy, creates an opening so that urine can pass out of the body through the abdominal wall.

Pelvic exenteration may be done to treat stage IV or recurrent colorectal cancer that has spread to nearby organs.

Find out more about pelvic exenteration.

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Surgery for metastases

Surgery may be done to remove colorectal cancer that has spread, or metastasized, to the liver or lungs.

Liver metastases

The surgeon may do a liver resection if there are only a few tumours in the liver or if the tumours can be removed while leaving enough working liver behind. This is surgery to remove part of the liver.

Radiofrequency ablation (RFA) may be used to treat liver metastases that can’t be removed with surgery. RFA is done with a special probe or needle inserted into the liver tumours to heat and destroy cancer cells using radiofrequency waves. RFA can be given through the skin, a cut or incision in the abdomen, or a laparoscopelaparoscopeA procedure that uses an endoscope (a thin, tube-like instrument with a light and lens) to examine or treat organs inside the abdomen and pelvis..

Find out more about liver metastases.

Lung metastases

A lung resection is surgery to remove part or all of a lung. It could be used to treat lung metastases if cancer hasn’t spread to any other organs and it is only in one area of the lung.

Find out more about lung metastases.

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Colostomy or ileostomy

Colostomy is a surgical procedure that creates a stoma (an artificial opening) from the colon to the outside of the body through the abdominal wall. Ileostomy is a surgical procedure that creates an opening from the ileum (the last part of the small intestine) to the outside of the body through the abdominal wall. These procedures allow stool, or feces, to leave the body after part or all of the colon is removed. The stool is collected in a special pouch on the outside of the body.

These surgeries are usually done after bowel resection. Whether or not you need a colostomy or ileostomy depends on the location of the cancer and how healthy the remaining colon is after bowel resection.

The colostomy or ileostomy can be temporary to allow the intestine to rest and heal after surgery. It may be permanent if the lower part of the rectum and anal sphincter are removed during bowel resection.

In some cases, the surgeon may do a diverting colostomy to prevent or manage a blockage in the intestine (called bowel obstruction). A diverting colostomy is a colostomy that doesn’t remove part of the intestine. It allows the stool to pass out of the body before it reaches the blocked part of the bowel.

Find out more about colostomy and ileostomy.

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Questions to ask about surgery

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

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