Sentinel Lymph Node Biopsy
Axillary Node Dissection
|Sentinel Lymph Node Biopsy
Axillary lymph node evaluation has been the standard of care in breast cancer treatment. This procedure involves the removal of 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.
For your convenience and information, we have included a list of Frequently Asked Questions specifically on sentinel lymph node biopsies.
One of the debilitating side effects of axillary dissection has been lymphedema (arm swelling). This occurs in approximately 8 to 10% of patients. 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).
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 procedure called cytokeratin staining. It generally takes 7 days to receive the results and 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 almost all breast cancer operations, 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 may be injected the day before surgery or the morning of surgery. It must remain in the breast for 3 to 4 hours before you are taken to the operating room.
At the time of surgery, after you are asleep, a vital blue dye may be injected behind the nipple. These two modalities allow us to identify the sentinel lymph node in greater than 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.
If the frozen section reveals spread of cancer cells to the lymph node, a level I and II 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.