Axillary surgery is performed during your breast cancer surgery to assess the extent of breast cancer involvement.
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 lymph node biopsy
If there is no evidence at diagnosis that the cancer has spread to the lymph nodes then a sentinel lymph node biopsy (SLNB) 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 breast.
A mapping process called lymphoscintigraphy can be used to identify the sentinel nodes before surgery. 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 compared to background tissue.
Some blue dye may also be injected which will make the first node(s) blue and visible to the naked eye. Blue dye used during sentinel node biopsy leaves some staining on the skin around the injection site but this fades over a few weeks. The dye is excreted via the kidneys so urine is coloured blue in the immediate post-operative period.
In some centres, blue dye alone may be used to locate the nodes as lymphoscintigraphy is available only in major cancer centres. (BCFNZ funded a pilot study to see whether a simple magnetic tracer can accurately locate the sentinel nodes.)
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.
Some centres use intra-operative frozen section to analyse the sentinel nodes and identify any cancer involvement allowing further axillary dissection to be performed at the time (if needed). In other centres, discussion about any need for further surgery takes place at a multidisciplinary meeting once all pathology results are known. If 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.
International clinical trials (American College of Surgeons Oncology Group Z0011 trial, and the International Breast Cancer Study Group Trial 23-01 and the AMAROS trial) suggest that, in patients with early breast cancer and low volume SLNB metastases (one to two nodes positive), there is no benefit from proceeding to axillary node dissection, in terms of disease-free survival, for patients who will have partial mastectomy and radiation therapy.
Your surgeon will discuss your surgical options with you.
The risk of developing lymphoedema following sentinel node biopsy alone is very low.
Axillary node dissection
When diagnostic tests before surgery have shown that there are cancer cells in lymph nodes, an axillary node dissection (AND) is needed to remove the nodes in levels one and two of the axilla. This might involve between five 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.
AND carries a higher risk of developing lymphoedema in the affected arm, compared to sentinel node biopsy.
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 undergoing radiation therapy will need to be able to lift their arms 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.