Breast Cancer Surgery

SENTINEL LYMPH NODE BIOPSY

Axillary lymph node evaluation has been the standard of care in breast cancer treatment. There are three levels of lymph nodes within the axilla. This procedure involves the removal of the lowest two levels of lymph nodes from the axilla (armpit) to determine if the cancer has spread locally. This is considered part of the staging of the breast cancer and is routinely done at the time of the definitive breast cancer surgery.

One of the debilitating side effects of axillary dissection has been lymphedema (arm swelling). This occurs in approximately 15-30% of patients. The frequency depends on individual patient factors and the use of radiation to the axilla. The arm may also become numb above the elbow at the level of the triceps muscle. You must protect your arm from cuts and scrapes for the rest of your life to prevent lymphangitis (an infection in the lymphatics of the arm).  For early detection of lymphedema using bioimpedience, click here.

In an attempt to better diagnose lymph node metastasis and decrease complications associated with axillary dissection, a method of lymph node mapping adopted from melanoma treatment has been used to identify the sentinel (the first line of defense) lymph node. This lymph node can be evaluated for microscopic metastasis through a special staining called cytokeratin staining. This methodology is far more sensitive than the naked eye of the pathologist.

We know that women previously thought to be node negative and, therefore, have local disease, have died of distant metastasis. This may be related to our previous inability to find these microscopic metastatic deposits and treat them aggressively with chemotherapy.

The absolute answers to these questions still have not been completely resolved. Sentinel lymph node identification is indicated in tumors under 2 cm, and is appropriate in both lumpectomy and mastectomy patients. Parameters may vary from surgeon to surgeon and will be based upon your individual tumor characteristics. The procedure to identify the node starts with an injection of radioactive tracer called technetium sulphur colloid. It is injected the morning of surgery just prior to you being taken back to the operating room.

At the time of surgery, after you are asleep, a vital blue dye may be injected around the tumor bed. These two modalities allow us to identify the sentinel lymph node in 90% of patients. When a sentinel lymph node is found at surgery, a frozen section (quick diagnoses) is performed. Once the sentinel node is identified, your surgeon will manually check your axilla for other nodes that may have tumor in them. Lymph nodes filled completely with cancer cells may not have the ability to pick up the radioactive tracer and blue dye; therefore, this is also an important part of the process.

If the frozen section reveals spread of cancer cells to the lymph node, a level I and II ( lowest two levels of lymph nodes) axillary node dissection is performed. If the frozen section is negative for spread of the cancer, then no further lymph node surgery is performed at that time. At your postoperative visit, you will discuss your final pathology, which will include the results of your margins of tumor resection and the cytokeratin staining (high tech evaluation for spread) for microscopic metastasis.

If the cytokeratin stains are positive, you may need to go back to the operating room for the completion of level I and II axillary node dissection to complete your staging. The need for further surgery will be discussed with your surgeon and medical oncologist.
 

Frequently Asked Questions

• If you identify a sentinel lymph node does that mean that the cancer has spread?
  NO. Finding a sentinel lymph node only means that we are able to find a node or nodes that has taken up the tracer or blue dye. It only identifies the lymph node that is at the highest risk to have metastatic cancer in it.
   
• Is the sentinel lymph node identification fool proof?
  NO. We believe that it is approximately 98% accurate in finding the first line of cancer spread. That means we could potentially miss one to two percent of cancer metastasis.
   
• Can there be more than one sentinel lymph node?
  YES. You can have several nodes show up with radioactive tracer. Usually only one is blue. On average two or three nodes are removed.
   
• Can I have an axillary node dissection if I want one?
  YES. Even if there is no evidence of spread in the sentinel lymph node, you are entitled to have levels I and II removed. It is still considered the standard of care.
   
• What happens if you can’t find a sentinel node or if more than one lights up?
  It is the surgeon’s judgment that determines if a node dissection needs to be completed. When in doubt, it is still the safest course and the surgeon should remove level I and II lymph nodes.
   
• Why wouldn’t a sentinel lymph node show up?
  Some tumors do not drain via the axillary lymphatics and therefore cannot be identified. Not finding a sentinel lymph node may also help the oncologist to determine the need for chemotherapy. Lymph nodes that are replaced completely with tumor may not take up the tracer.
   
• What happens to the radio-labeled tracer and the blue dye?
  It is excreted in the urine and, therefore, you will see blue urine for 24 to 48 hours after surgery. Your skin may also have a blue discoloration on the breast.
   
• Do I have to spend the night in the hospital?
  If you require an axillary node dissection you will have a drain and may be kept overnight. If your node is negative you should be able to go home the same day. 

Contact Dr. Lisa Curcio to discuss your risk for breast cancer . Dr. Curcio is a breast cancer heredity risk specialist and she can advise you on your breast cancer risk.

Visit "Advanced Breast Care Specialists of Orange County"  in Mission Viejo, California.