Surgery On The Axillary Lymph Nodes Continues To Evolve
The modern era of lymph node surgery began at the turn of the last century with a surgeon named William Halstead. He developed a breast cancer procedure that included removing the breast, chest wall muscles, and the underarm lymph nodes (axillary lymph nodes). It included the removal of 3 levels of nodes and was called an axillary node dissection. Level 1 nodes are the lymph nodes that can be felt nearest the breast. Level 2 nodes are much deeper and cannot generally be felt. Deeper yet are level 3 nodes and are located beneath the collar bone. This type of surgery carried with it a very high incidence of lymphedema. Removal of these three levels lasted until the 1980s, when removal of level 3 was omitted. It is to this day. still unclear whether eliminating level 3 reduced the risk of lymphedema.
In the 1990s, a new procedure was developed that was destined to significantly reduce the number of women requiring a complete axillary node dissection. This procedure was called a sentinel node biopsy. In this instance, a blue or radioactive dye or both were injected into the breast preoperatively. A small incision was then made under the arm, and only the lymph nodes harboring the dye were removed. Sentinel node biopsy accounted for a drop in lymphedema incidence 3-5% from 20-35% seen in axillary lymph node dissection. Axillary node dissection was reserved for those women whose sentinel node harbored cancer cells. Sentinel node biopsy has likely saved 70% of women with breast cancer from having an axillary node dissection.
In 2011, results of another clinical trial were to have an immediate impact on axillary lymph node surgery. This trial determined that women undergoing lumpectomy and radiation for breast cancer treatment did not benefit from axillary node dissection even if they had 1 or 2 lymph nodes found to contain cancer. Again, this saw a dramatic reduction in the number of women subjected to potential lymphedema development. However, this did not apply to women undergoing mastectomy who had positive lymph nodes, only to those having lumpectomy and radiation.
So, as we entered the 2010s, some women might still be subjected to axillary node dissection. These included those women undergoing mastectomy with lymph nodes containing cancer, women with cancerous lymph nodes after chemotherapy, and those with greater than two cancerous nodes who had undergone lumpectomy. However, one group of women might escape axillary node dissection due to a new procedure based on new and exciting technology. An explanation of this technology requires some digression. Our ability to diagnose cancerous lymph nodes prior to surgery using ultrasound has increased dramatically in recent decades. Those patients diagnosed with cancer in one or more lymph nodes prior to surgery usually underwent chemotherapy before surgery (called neoadjuvant chemotherapy). Until recently, these patients universally underwent axillary node dissection even if the chemotherapy had eliminated all cancer from the nodes. Enter a new device in which a small clip, visible to radar, is inserted into all apparent cancerous nodes prior to chemotherapy. At surgery, following chemotherapy, a hand-held radar detector is used to find the lymph nodes with the radar-detectable seeds. This procedure is called a targeted axillary node dissection. If the lymph nodes are cancer-free, no additional lymph nodes are removed.
In summary we have come a long way in eliminating axillary lymph node dissection and the potential for lymphedema. It is unlikely that we are through. Our ability to treat cancers based solely on the genes that are “expressed” by each cancer may eventually eliminate lead to individualized targeted therapy, our need to remove any lymph nodes when treating cancer. Stay tuned.