Consensus Statement on Guidelines for Performing
Sentinel Lymph Node Dissection in Breast Cancer
This statement updates the Original Guidelines
(November 1998), First Revision (August 2000), Second Revision
(November 2002), Third Revision (October 2003), Fourth Revision
(December 2005).
For staging patients with invasive breast
cancer, sentinel lymph node dissection (SLND) is a minimally
invasive alternative to axillary lymph node dissection (ALND).
As confirmed by multiple studies drawn from a wide range of
practice settings, the staging accuracy of SLND, properly performed,
is at least equal to that of ALND (occasional false negatives
offset by improved detection), and the morbidity of SLND is
less. For these reasons, SLND has become the preferred practice
for most surgeons who treat breast cancer.
1) Indications and contraindications:
Early reports notwithstanding, the current body of reported
surgical experience shows that SLND is suitable for virtually
all clinically node-negative T1-3 invasive breast cancers,
including patients with multifocal/multicentric disease and
prior breast surgery. More limited - but reasonable - data
suggest that SLND is feasible following axillary surgery
of minimal extent, especially a previous SLND, following
radiotherapy, and following neoadjuvant chemotherapy. The
decision to apply SLND in these situations requires individualized
surgical judgement and fundamentally requires an unequivocally
successful mapping procedure. If the identification of a
sentinel node is in doubt by established technical criteria,
standard axillary dissection is advised. SLND should be considered
for DCIS whenever mastectomy is required or when invasive
disease is suspected. The role of SLND for inflammatory breast
cancer remains undefined.
2) The positive SLN:
Outside of clinical trials, usual treatment for SLN-positive
patients is a level I-II ALND. However, since axillary node metastases
are limited to the SLN in more than half of SLN-positive individuals,
there may be low-risk subsets for whom a completion ALND is not required.
The decision to omit completion axillary dissection in such a case requires
a balanced discussion between the surgeon and the patient regarding
the risks of further surgery and any potential for improved outcome
with more complete information and/or axillary clearance.
3) Credentialing and privileging:
The credentialing and privileging of SLND should be done in
accordance with the policies and procedures of each local
hospital. The best available retrospective data suggest that
20 SLND procedures validated by an ALND (or mentored by an
experienced colleague) are optimal to minimize false-negative
results, and we recommend obtaining this level of experience
before performing SLND on its own. However, the learning
curve for SLND may not be this long: recent prospective data
show that for surgeons using a well-standardized technique,
the learning curve for SLND may be much shorter, with most
failed results occurring in the first few cases done.
4) Technique:
The success of SLND is maximized, and the false-negative rate
minimized, by a technique which combines careful intraoperative digital
examination, blue dye and isotope mapping. Sentinel node staging programs
with the lowest false negative rates report an average yield of two
sentinel nodes per dissection (some cases with less some cases with
more).
5) Morbidity and long-term results:
The morbidity of SLND (including lymphedema), while significantly
less than that of ALND, is not zero. However, axillary recurrence
after a negative SLND has to date proven to be a very rare
event. We encourage all surgeons performing SLND to track
their long-term results by contributing to local or national
registries, and by enrolling their patients in clinical
trials.
Approved December 8, 2005
Board of Directors
The American Society of Breast Surgeons
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