In response to the increasing use of sentinel lymphadenectomy, a panel convened by the American Society of Breast Surgeons has issued a revised consensus statement on performance and utilization criteria for sentinel lymphadenectomy.
The statement, which outlines performance criteria for surgeons who use the procedure, identifies patients who are ineligible for the procedure, and encourages surgeons to participate in established national registries and clinical trials, follows below. Additional copies of the consensus statement are available from the Society at 301-362-1722.
Dr. Michael J. Edwards, associate professor of surgery, division of surgical oncology, University of Louisville, headed the panel, which included Dr. Armando E. Giuliano, chief of surgical oncology at the John Wayne Cancer Institute in Santa Monica, California; Dr. Douglas Reintgen, professor of surgery at the H. Lee Moffitt Cancer Center and Research Institute, University of South Florida; Dr. Lorraine Tafra, director, Breast Center of Anne Arundel Medical Center, Annapolis, Maryland, and Dr. Pat Whitworth, director, Nashville Breast Center, Nashville, Tennessee.
Revised Consensus Statement on Guidelines for Performance of Sentinel Lymphadenectomy for Breast Cancer
Sentinel lymphadenectomy is a minimally invasive staging procedure for patients with breast cancer. Sentinel lymphadenectomy, when performed in conjunction with axillary dissection, enhances staging accuracy by identifying occult deposits of microscopic disease that are undetected by routine histological examination of the standard axillary dissection specimen. Sentinel lymphadenectomy, when performed in lieu of axillary dissection, is associated with less morbidity and is potentially more cost effective. Multiple studies from tertiary centers with a high volume of experience, and the data from two national registries of community surgical experience show that sentinel lymphadenectomy, when performed by experienced surgeons, is of equivalent or superior diagnostic staging accuracy. However, the degree of experience required to reliably and accurately perform the procedure, while becoming better understood, is not completely defined.
In regard to sentinel lymphadenectomy for breast cancer, the American Society of Breast Surgeons has updated and revised our prior statement and acknowledges the following:
(1) Patients with palpable, suspicious, metastatic axillary lymph nodes should not be considered for sentinel lymphadenectomy. In addition, sentinel lymphadenectomy may be unreliable for patients with multifocal malignancies, for those patients with a history of previous chemotherapy or radiation therapy for breast cancer, and for patients with histories of either extensive prior breast or axillary surgery. Sentinel lymphadenectomy in this setting should be performed only as part of a research protocol.
(2) Axillary treatment for patients with metastatic disease found in sentinel lymph node remains controversial. Until further multicenter trial results are available, a staging level I and II lymph node dissection is recommended outside of the clinical trial setting.
(3) The credentialing and privileging of sentinel lymphadenectomy, as with any surgical procedure, are by the policies and processes of each local hospital. Each hospital will define its own criteria for accepting the findings of sentinel lymphadenectomy in lieu of axillary dissection and it is encouraged that this is done in partnership with an experienced staff breast surgeon. The Society recognizes the controversy regarding the level of experience sufficient for accepting the results of sentinel lymphadenectomy as the staging procedure of choice in the clinical setting where the results are used to determine indications for systemic therapy. Information from two national registries quantifying the community experience was presented at the year 2000 annual meeting of the American Society of Breast Surgeons. Findings from these registries indicated that an approximate 10 case experience is necessary for a ³ 85% success in identifying an axillary sentinel lymph node. More importantly, data from these two databases indicate that an individual surgical experience of at least 20 cases of sentinel lymphadenectomy, where both sentinel lymphadenectomy and axillary dissection are performed, is necessary to minimize the risk of false-negative results. The false-negative rate (ie, the ratio of the number of false-negative biopsies to the number of patients with positive lymph nodes) is the most important factor regarding accurate sentinel lymph node staging. Past experience suggests an acceptable average false-negative rate in the range of 5%.
(4) The impact on a surgeon’s experience by proctored cases, and formal training in accredited continuing medical education courses is thought to reduce the personal case experience necessary to achieve optimal results, but is yet to be quantitated.
(5) After abandoning axillary dissection in favor of sentinel lymphadenectomy, surgeons should continue to report their axillary recurrence rate. This rate should be less than 5%. Surgeons are encouraged to report their experience by contributing to national registries and enrolling patients in clinical trials.