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Surgical techniques for women with breast cancer have improved over the past decade, with more choices for women than ever before. Surgery is the most common local treatment for breast cancer.

Here is a summary of the types of breast cancer surgeries:

Breast-conserving surgery

This type of surgery, also known as breast-conserving surgery, aims at keeping the breast and only removing the tumour and a small amount of normal tissue around it. 

Lumpectomy (or partial mastectomy) is the most common type of breast-conserving surgery. This procedure usually involves a small incision above the area where the cancer is. The surgeon removes the tumour as well as some normal tissue around it.

  • Partial mastectomy may also be referred to as “segmental resection or mastectomy" or "wide excision".

  • Some doctors use the terms "partial mastectomy” and "lumpectomy" interchangeably.

  • Be clear on how your doctor uses these terms and ask him or her to clearly describe what each procedure is.



This type of surgery removes the breast, the nipple and excess skin and may or may not remove the lymph nodes. There are several types of mastectomies:

Simple (or total) mastectomy removes the entire breast including the nipple and any excess skin. The surgeon may also add a sentinel node biopsy, which includes the removal of the sentinel lymph nodes without removing any of the muscles.

Modified radical mastectomy removes all of the breast tissue, axillary lymph nodes, excess skin and the nipple. The surgeon may perform a modified radical mastectomy.

A mastectomy could be done for the reasons below, but axillary node dissection is done when cancer has spread to the lymph nodes:

  • When radiation therapy is not available or can’t be given because of a specific health condition.

  • When the size of the tumour is large in comparison with the size of the breast.

  • When there is more than one site of cancer situated in different areas of the breast.

  • If the patient has had previous radiation to the affected breast.

  • If he or she is unable to remove the tumour with a sufficient amount, or margin, of normal tissue surrounding it.

  • If the patient prefers to have a mastectomy after discussing breast-conserving surgery.

Radical mastectomy, was the “original" surgery for breast cancer and is now very rarely done. It involves the removal of the breast, chest wall muscles, some nerves, the nipple, skin and all of the lymph nodes in the armpit right up to the collarbone.  


Additional surgical procedures:

Sentinel node biopsy avoids the need to remove lymph nodes that are not cancerous. This procedure was developed to avoid the procedure with the armpit and to learn more about which lymph nodes should be removed.  

An injection of a tracer is done the day before or the day of surgery to help the surgeon locate the first lymph nodes under the arm on the affected side called sentinel (guard) lymph nodes. The surgeon will remove between one and four lymph nodes. Only the nodes that pick up the tracer will be removed and tested. The nodes removed are then sent to the lab and are examined by the pathologist, who will determine if they contain cancer or if they are cancer free.

During axillary lymph node dissection, the surgeon will remove a group of lymph nodes in the armpit on the affected side to help determine what kind of therapy you will receive after your surgery. You will not know how many lymph nodes were removed until the pathology report comes back. The surgeon does not remove the lymph nodes one by one, but instead takes an area of tissue from under the arm. Some nodes may contain cancer and some may be cancer free. All will be examined and tested by the pathologist to determine the number of lymph nodes that contain cancer.

Whether you have a lumpectomy or a mastectomy, you and your surgeon may choose to remove some of the nodes in your armpit to:

  • Help remove cancer that may have spread to the lymph nodes.

  • Study nodes under a microscope to help determine what kind of therapy you will receive after your surgery.

Removal of lymph nodes may contribute to lymphedema, a swelling of the arm on the affected side caused by an abnormal build-up of fluid.

The risk of lymphedema is anywhere from five to 17 per cent for those having a sentinel lymph node biopsy, and about 20 to 53 per cent for those having an axillary lymph node dissection.

What happens after surgery? Will I need to undergo more treatment?

  • Not necessarily. Your doctors will assess your tumour and decide if additional treatment might benefit you. This additional treatment is known as adjuvant therapy​

How will my healthcare team decide if I need adjuvant therapy?

  • There are several factors that your healthcare team will consider, including the chance of recurrence. If it’s determined that the risk of your cancer returning is high, then your doctor may recommend adjuvant therapy to help reduce this risk.