Surgery for cancer

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Surgery is a medical treatment to examine, remove or repair tissue. It is usually done by cutting into the body. There are many reasons to use surgery for cancer.

Diagnose and stage cancer

Doctors usually do a biopsy to diagnose cancer. A biopsy removes tissues or cells from the body so they can be examined under a microscope to check for cancer cells. A biopsy can be done using radiology or surgery. A pathologist is a doctor that studies the tissues and cells removed from the body. They prepare a pathology report to give the results of what they find. Find out more about biopsies and cell and tissue studies.

Doctors may sometimes use surgery to find out the stage of a cancer, but they usually use imaging tests instead. The stage describes how much cancer there is in the body and where it is (the extent of cancer). Find out more about staging cancer.

A biopsy and surgery help your doctor find out:

  • the exact type of cancer
  • the grade of the cancer
  • the size of a tumour
  • how deep a tumour has grown into layers of tissue
  • if the cancer cells that are seen in any part of the tissue that is removed are also present in the edges of the tissue (called positive surgical margins)
  • if any nearby lymph nodes or organs have cancer in them

Your healthcare team uses the information learned from a biopsy and surgery to decide what type of treatments to offer.

Remove cancer

Surgery to remove cancer from a specific place in the body is a standard treatment for many types of cancer. Surgery is most often combined with other treatments. Using surgery to remove cancer is most effective when the cancer is only in the place where it started (called localized) and hasn't spread to other parts of the body (called metastases).

During surgery, the surgeon removes the cancer along with some normal tissue around it. This is done to make sure that there are no cancer cells left behind and lower the chance of the cancer coming back (recurring). If cancer cells cannot be completely removed, the cancer may come back.

Depending on the type of cancer, the surgeon may also remove lymph nodes close to the tumour. Lymph nodes are removed by a lymph node dissection or a sentinel lymph node biopsy. The lymph nodes are sent to a lab to be examined under a microscope to see if they have cancer cells in them. If the lymph nodes are not removed and they contain cancer cells, these cells may form new tumours or spread to other parts of the body. Removing lymph nodes can help doctors decide if systemic treatment is needed. Find out more about lymph node dissections and sentinel lymph node biopsies.

Surgery may also be used to treat cancer that has spread from where it started (called the primary site, or primary tumour) to other parts of the body. The new tumour is called a metastasis.

Sometimes it is not possible to remove all of the cancer. This can happen when the tumour is in a place where it's too hard to remove without damaging other organs or areas. In some cases, surgery may still be done to remove as much of the cancer as possible. This is called debulking or cytoreductive surgery. Removing as much cancer as possible may be done as a palliative treatment or to make it easier for other treatments to destroy the cancer.

Surgeons will try to do as little damage as possible during surgery to remove cancer. They will try to limit how much tissue they remove. Surgeons take many steps and follow special procedures to avoid cutting into a tumour when they do surgery to remove it. This lowers the chance that the cancer cells will spread to other areas.

Cancer does not get worse when it comes in contact with the air. The air does not cause cancer to grow faster or spread to other parts of the body.

Lower the chance of the cancer coming back

Along with removing some normal tissue around the cancer, surgeons may also remove other normal areas nearby, such as muscles, nerves and lymph nodes. The surgeon may remove these areas even if there is no evidence that they contain cancer. Research shows that removing nearby structures can lower the chance of the cancer coming back.

Relieve symptoms

Surgery may be used to relieve and control symptoms of cancer (also called palliative surgery). For example, surgery may be used to go around (bypass) a blocked area. It can also be used to control pain or bleeding caused by a tumour.

The surgeon will discuss the risks and benefits of doing surgery, especially when the goal is to control symptoms and improve the quality of life rather than treat the cancer.

Fix damaged areas

Surgery may be used to fix or rebuild areas that are damaged by cancer or cancer treatments. This is called reconstructive surgery. It may be used to help part of the body work like it did or look like it did before cancer or the treatments.

Surgeons can use different techniques to fix or rebuild body parts. These techniques include tissue flaps or grafts, implants and prostheses.

Keep your body working

You may need surgery to help keep your body working properly. This includes things like breathing and eating.

For example, people with head and neck cancers may need a tracheostomy. A tracheostomy is surgery to make an opening through the neck into the windpipe (trachea). This opening is used to place a breathing tube so air can get to the lungs and help you breathe.

Sometimes people with cancer need help getting enough nutrition. You may not be able to eat or drink by mouth, or may only be able to eat small amounts each day. Doctors can use surgery to place a tube directly into the stomach or small intestine. A special liquid mixture of nutrients is given through this tube. Nutrition can also be given by intravenous (IV) directly into the blood. Find out more about tube feeding and intravenous (IV) nutrition.

Support other treatments

The surgeon may insert a special tube called a central venous catheter with surgery. It is used to take blood samples or give you chemotherapy, antibiotics, blood products or IV nutrition. Find out more about central venous catheters.

Surgery may also be used to place a special pump that is used to deliver chemotherapy drugs.

Prevent cancer

Preventive (prophylactic) surgery is used to lower the risk of developing certain types of cancer. It is done before cancer develops. The surgeon removes tissue that is not yet cancer but has a higher chance of becoming cancer, such as a precancerous condition.

If you have an inherited condition that puts you at high risk for developing a certain type of cancer, your healthcare team may offer preventive surgery. The surgeon may remove large amounts of tissue or an entire organ to help lower your risk of developing that cancer. For example, someone who has a very high risk of developing breast cancer may choose to have one or both breasts removed before cancer develops (called a prophylactic mastectomy).

Questions to ask about surgery

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

Expert review and references

  • Gary Groot, MD, PhD, FRCSC
  • American Cancer Society. How Surgery Is Used For Cancer. 2019:
  • American Society of Clinical Oncology (ASCO). What is Cancer Surgery?. 2021:
  • Vasudevan SA, Whitlock RS, Weldon CB, Nuchtern JG. General principles of surgery. Blaney SM, Adamson PC, Helman LJ (eds.) . Pizzo and Pollack's Pediatric Oncology. 8th ed. Wolters Kluwer ; 2021 : Kindle version, chapter 15. .
  • Cancer Care Ontario. Cancer Treatments: Surgery. Monday, November 14, 2022.
  • Cancer Research UK. What is Cancer Surgery. 2022:
  • Macmillan Cancer Support. Surgery. 2020:
  • National Cancer Institute. Surgery to Treat Cancer. National Institutes of Health; 2015:

Types of cancer surgery

Several different types of surgery may be done to help diagnose and treat cancer.

Having surgery

Surgery can be done in a doctor’s office, clinic or hospital operating room.

Side effects of surgery

Side effects can happen with any type of cancer surgery, and may include pain and bleeding.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

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