A Limited Number of Sentinel Nodes Accurately Stages the Axilla
MB Alikhan, TT Ha, N Jaskowiak, HA Sattar. University of Chicago, Chicago, IL
Background: Axillary lymph node status is the single most important prognostic factor in patients with breast cancer. Over the past decade, sentinel lymph node biopsy (SLNB) has become the standard of care for axillary staging. However, limited studies address the question of how many sentinel nodes need to be biopsied to ensure adequate screening, especially in the era of pre-screening with axillary ultrasound and ultrasound-guided axillary lymph node sampling.
Design: We reviewed all cases of positive sentinel lymph node biopsy during a four year period to determine how many nodes needed to be sampled for accurate staging. During this time, all patients at the University of Chicago Medical Center were pre-screened with axillary ultrasound and, when warranted, underwent ultrasound-guided biopsy. A positive biopsy alleviated the need for SLNB and, hence, these patients were not considered in our study.
Results: We identified 348 patients who underwent SLNB (2004-2008) at the University of Chicago Medical Center. SLNB identified carcinoma in the axillary nodes of 67 of these patients. In all, 191 lymph nodes were recovered from this group (range 1-6; mean 2.8). The excison of the first sentinel node was sufficient for a positive diagnosis in 76% of these cases, excision of a second node increased the capture rate to 91%, while a third node increased it to 96%, and removal of a 4th node captured all patients with a positive sentinel node. Interestingly, two patients with nodal disease had negative sentinel nodes, but positive non-sentinel nodes palpated and excised by the surgeon during SLNB. During this same period of time, 281 patients underwent SLNB with no evidence of metastatic disease in the axilla. In all, 766 lymph nodes were recovered from this group (range 1-11; mean 2.75).
Conclusions: Excision of four sentinel nodes accurately identified all cases of positive sentinel node in our study. Excision of greater than 4 nodes does not lead to additional prognostic information and instead consumes valuable anesthesia, surgeon, and pathologist time while providing limited benefit to the patient. Larger studies are necessary to further support this conclusion.
Wednesday, March 24, 2010 9:30 AM
Poster Session V # 42, Wednesday Morning