American Society of Breast Surgeons Issues New Statement on Sentinel Lymphadenectomy

In response to the increasing use ofsentinel lymphadenectomy, a panel convened by the American Society of Breast Surgeons has issued a revisedconsensus statement on performance and utilization criteria for sentinellymphadenectomy.

The statement, which outlines performance criteria for surgeonswho use the procedure, identifies patients who are ineligible for the procedure,and encourages surgeons to participate in established national registries andclinical trials, follows below. Additional copies of the consensus statement areavailable from the Society at 301-362-1722.

Dr. Michael J. Edwards, associate professor of surgery, divisionof surgical oncology, University of Louisville, headed the panel, which includedDr. Armando E. Giuliano, chief of surgical oncology at the John Wayne CancerInstitute in Santa Monica, California; Dr. Douglas Reintgen, professor ofsurgery at the H. Lee Moffitt Cancer Center and Research Institute, Universityof South Florida; Dr. Lorraine Tafra, director, Breast Center of Anne ArundelMedical Center, Annapolis, Maryland, and Dr. Pat Whitworth, director, NashvilleBreast Center, Nashville, Tennessee.

Revised Consensus Statementon Guidelines for Performance of Sentinel Lymphadenectomyfor Breast Cancer

Sentinel lymphadenectomy is a minimally invasive stagingprocedure for patients with breast cancer. Sentinel lymphadenectomy, whenperformed in conjunction with axillary dissection, enhances staging accuracy byidentifying occult deposits of microscopic disease that are undetected byroutine histological examination of the standard axillary dissection specimen.Sentinel lymphadenectomy, when performed in lieu of axillary dissection, isassociated with less morbidity and is potentially more cost effective. Multiplestudies from tertiary centers with a high volume of experience, and the datafrom two national registries of community surgical experience show that sentinellymphadenectomy, when performed by experienced surgeons, is of equivalent orsuperior diagnostic staging accuracy. However, the degree of experience requiredto reliably and accurately perform the procedure, while becoming betterunderstood, is not completely defined.

In regard to sentinel lymphadenectomy for breast cancer, theAmerican Society of Breast Surgeons has updated and revised our prior statementand acknowledges the following:

(1) Patients with palpable, suspicious, metastatic axillarylymph nodes should not be considered for sentinel lymphadenectomy. In addition,sentinel lymphadenectomy may be unreliable for patients with multifocalmalignancies, for those patients with a history of previous chemotherapy orradiation therapy for breast cancer, and for patients with histories of eitherextensive prior breast or axillary surgery. Sentinel lymphadenectomy in thissetting should be performed only as part of a research protocol.

(2) Axillary treatment for patients with metastatic diseasefound in sentinel lymph node remains controversial. Until further multicentertrial results are available, a staging level I and II lymph node dissection isrecommended outside of the clinical trial setting.

(3) The credentialing and privileging of sentinellymphadenectomy, as with any surgical procedure, are by the policies andprocesses of each local hospital. Each hospital will define its own criteria foraccepting the findings of sentinel lymphadenectomy in lieu of axillarydissection and it is encouraged that this is done in partnership with anexperienced staff breast surgeon. The Society recognizes the controversyregarding the level of experience sufficient for accepting the results ofsentinel lymphadenectomy as the staging procedure of choice in the clinicalsetting where the results are used to determine indications for systemictherapy. Information from two national registries quantifying the communityexperience was presented at the year 2000 annual meeting of the American Societyof Breast Surgeons. Findings from these registries indicated that an approximate10 case experience is necessary for a ³ 85% success in identifying an axillarysentinel lymph node. More importantly, data from these two databases indicatethat an individual surgical experience of at least 20 cases of sentinellymphadenectomy, where both sentinel lymphadenectomy and axillary dissection areperformed, is necessary to minimize the risk of false-negative results. Thefalse-negative rate (ie, the ratio of the number of false-negative biopsies tothe number of patients with positive lymph nodes) is the most important factorregarding accurate sentinel lymph node staging. Past experience suggests anacceptable 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 isthought to reduce the personal case experience necessary to achieve optimalresults, but is yet to be quantitated.

(5) After abandoning axillary dissection in favor of sentinellymphadenectomy, surgeons should continue to report their axillary recurrencerate. This rate should be less than 5%. Surgeons are encouraged to report theirexperience by contributing to national registries and enrolling patients inclinical trials.