[294] Number of Positive Sentinel Nodes after Pre-Screening with Axillary Ultrasound Is Predictive of Overall Axillary Tumor Burden in Breast Carcinoma

Rebecca J Wolsky, Corey B Bills, Husain Sattar. University of Chicago, Chicago, IL

Background: Axillary lymph node status is the most useful prognostic factor in patients with breast cancer. The current standard of care for screening the axilla is sentinel lymph node biopsy (SLNB). More recently, axillary ultrasound (AUS) with biopsy has become an important pre-screening modality. This study aims to determine the relationship of the number of positive sentinel nodes with final nodal stage in patients who have been pre-screened with AUS. Such information is useful as recent studies suggest complete axillary lymph node dissection does not confer added survival benefit over SLNB alone in patients with limited axillary disease.
Design: Surgical pathology reports and slides were reviewed from 461 consecutive breast cancer patients (University of Chicago Archive, 2004-2008) who had undergone pre-screening with axillary ultrasound. Of these, 348 cases that were deemed node-negative then underwent SLNB to confirm the AUS findings. 67 cases (19.3%) proved to be false negative, revealing metastatic carcinoma on sentinel lymph node biopsy. These cases were further reviewed to determine whether the number of positive sentinel nodes was predictive of final number of nodes involved.
Results: Of the 67 cases with a negative axillary ultrasound in which SLNB revealed metastatic carcinoma, an average of 3 sentinel nodes were removed (range 1-6). The relationship of the number of positive sentinel nodes to the final number of positive nodes is shown in Table 1.

Table 1: Relationship of Final Nodal Status to Number of Positive Sentinel Nodes
Number of Positive Sentinel NodesAverage Total Number of Positive Nodes
1 (n=45)1.67
2 (n=16)4.94
3 or more (n=5)11.2



Conclusions: After pre-screening with AUS, the number of positive sentinel nodes is predictive of the final number of positive axillary nodes (p <0.0001) with fewer positive sentinel nodes corresponding to lower axillary tumor burden overall. Recent studies suggest that axillary lymph node dissection (ALND) does not offer a survival advantage in patients with limited axillary disease who are treated with breast-conserving surgery, whole-breast irradiation, and adujuvant systemic therapy. The use of a pre-screening modality such as AUS in combination with SLNB may be useful in identifying patients for whom ALND is not beneficial.
Category: Breast

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 13, Wednesday Morning

 

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