Breast cancer

Axillary surgery

Axillary surgery is performed during your breast cancer surgery, and is to remove any lymph nodes with cancer cells in them.


This helps to determine the stage of your cancer and plan the best treatment for you.It also provides the opportunity to remove any involved lymph nodes.

If you have an invasive (infiltrating) breast cancer then some form of lymph node surgery in the underarm (axilla) will be recommended. If you're having breast conserving surgery this is done through a separate incision in the armpit, and if you're having a mastectomy, it's done through the mastectomy incision.

Types of axillary surgery

Sentinel node biopsy

If there is no evidence at diagnosis that the cancer has spread to the lymph nodes then a Sentinel Node Biopsy will be performed.

The sentinel node(s) is the first draining lymph node(s) in the chain of nodes in the underarm which drain lymphatic fluid from the area of the tumour.

These can be identified before surgery by using a mapping process called lymphoscintigraphy. This involves injecting a small amount of radioactive tracer fluid into the breast, usually around the areola. The sentinel node(s) will be the first to take up this fluid. A scan is performed to provide an image which identifies the location of the correct node(s) for the surgeon to remove.

In the operating room the surgeon uses a hand-held gamma probe to locate the node(s) which will have a higher radiation count than background tissue. Some blue dye may also be injected which will make the first node(s) blue and visible to the naked eye.

When the sentinel node(s) has been removed the pathologist examines it under a microscope. If no cancer cells are seen then no further nodes need to be removed. If the sentinel node is positive then an axillary node dissection may be performed to remove more lymph nodes or radiation treatment of the axilla may be advised.

If, after the surgery, the pathology report identifies only isolated tumour cells in the sentinel node, further surgery is not recommended as the chance of further involvement is low. If micrometastases ( deposits measuring less than 2mm) are identified, further axillary dissection is no longer considered to be essential as enough prognostic information has been obtained and when appropriate adjuvant treatment is given the risk of recurrence in the axilla is low.

The risk of developing lymphoedema following sentinel node biopsy alone is very low.

Read more about lymph node mapping.

Axillary node dissection

. When diagnostic tests before surgery have shown that there are cancer cells in a lymph node, an axillary node dissection is needed to remove the nodes in levels one and two.This might involve between 5 and 30 nodes as the number of lymph nodes located in each level varies from person to person.

There are three levels of lymph nodes in the axilla but level three nodes are not routinely removed, as this greatly increases the risk of lymphoedema and shoulder problems without improving cancer outcomes.

The removed nodes will be examined by the pathologist and the pathology report will indicate how many nodes were removed and how many contained cancer cells.

Axillary node dissection carries an approximately 10-20% risk of developing lymphoedema in the affected arm.

International clinical lrials are currently investigating whether people with 1-2 positive sentinel nodes, who will undergo appropriate adjuvant treatment,require further axillary dissection. Until these results are known, the current best practice is to perform level 2 axillary dissection.

Post-op care

Axillary node dissection can sometimes result in stiffness in the arm and shoulder, particularly if the arm is not gently exercised during the recovery period. Before going home from hospital you will be given instructions about arm/shoulder exercises. It's important to follow these instructions to regain and preserve a normal range of movement. Patients who undergo radiation therapy will need to be able to lift their arm above their head while the treatment is being administered. If you are experiencing difficulty with the exercises then a referral to a physiotherapist will help you to regain your mobility.

Side-effects of axillary surgery

Surgery to the axillary region can result in seroma, cording, numbness, pain or lymphoedema.

See surgery side-effects for more information.

Watch: Exercises after breast surgery