The National Comprehensive Cancer Network (NCCN) recently updated their guidelines to include sentinel node biopsies in eligible patients diagnosed with breast cancer.
The NCCN consists of a panel from 18 of the nation’s most reputable cancer treatment facilities. The panel sets clinical guidelines that are continually refined and include algorithms for diagnostic procedures and treatment of cancer. For 2002, the NCCN has fine-tuned recommendations for the use of sentinel node biopsies in patients diagnosed with breast cancer. According to the NCCN database, the use of sentinel node biopsies has increased from 9% to 59%, indicative of the growing interest of patients for receiving this procedure.
The 2002 NCCN guidelines indicate that sentinel node biopsy (SNB) may be considered an option for patients if all of the following criteria are met: patients are diagnosed with stage I or II; there is only one cancer site in the breast; the cancer is less than 5 centimeters in largest diameter; the patient has had no prior excision greater than 6 centimeters; the patient has received no prior chemotherapy or hormone therapy; and the procedure is performed by an experienced sentinel node team. The medical team must have documented experience with sentinel node biopsies in breast cancer and must include a surgeon, radiologist, nuclear medicine physician and pathologist who have had prior discussion with medical and radiation oncologists on the use of sentinel node for treatment decisions.
For over 30 years, the standard of practice for breast cancer staging has included the removal of axillary (under the arm) lymph nodes to aid in determining the spread of cancer in the body. If cancer spreads from its site of origin, it is thought to spread first to the lymph nodes that initially collect the excess lymph fluid from that area (sentinel lymph nodes). With current standard staging procedures, axillary lymph nodes are removed during surgery and are tested to determine if they contain breast cancer cells. The presence or absence of cancer cells in axillary lymph nodes is an essential factor in defining optimal treatment strategies following surgery. Women who have cancer cells present in their axillary lymph nodes are thought to have cancer that has spread and therefore require adjuvant systemic (full-body) therapy.
Unfortunately, the removal of axillary lymph nodes (approximately 10-25 nodes) may be associated with chronic side effects including pain, infection, limited shoulder motion, numbness and lymphedema (swelling of the arm due to an accumulation of lymph fluid). Since these complications can become debilitating, the strategy of sentinel lymph node dissection is currently being evaluated and refined. This strategy incorporates the removal of only the sentinel lymph node(s) to determine the extent of cancer spread. Because the sentinel lymph node(s) receives initial drainage from the cancer, it has the highest probability of containing cancer cells if the cancer has spread. Therefore, the removal of other axillary lymph nodes may be unnecessary if no cancer cells are present in the sentinel node. If accurate, this practice could eliminate the need for standard axillary node dissection and its complications.
The precision in correctly identifying the sentinel node is imperative in order for this procedure to provide accurate results. Currently, there are two methods that are commonly used together: 1) injections of blue dye in the area immediately encompassing the cancer, 2) injections of a radioactive substance in the area immediately encompassing the cancer. The injections are administered prior to surgery. During surgery, the surgeon identifies the node(s) containing either the blue dye (through direct visualization) or the radioactive substance (through a hand-held probe that detects radioactivity), indicating the collection of drainage from the cancer. The node(s) that collects the injected substances is determined to be the sentinel node and is subsequently removed.
The NCCN cautions that SLB has not demonstrated an improvement in survival over axillary node dissection and participation in clinical trials further evaluating the procedure is encouraged. Patients who are candidates under the NCCN guidelines for SLB may wish to speak with their physician about the risks and benefits of SLB, assistance in locating an experienced SLB medical team to perform the procedure and/or participation in a clinical trial evaluating SLB. Sources of information regarding ongoing clinical trials include the National Cancer Institute.
Reference: Statement of the National Comprehensive Cancer Network on guidelines for sentinel node biopsy in invasive cancer. Hollywood, FL: National Comprehensive Cancer Network; Feb 9 – March 3, 2002.