[295] Efficacy of Axillary Ultrasound Pre-Screening in Relation to Pathologic Parameters of 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. The purpose of this study is to correlate pathologic features of breast cancer with successful or unsuccessful AUS.
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 AUS. These cases were categorized into true positive, false positive, true negative, and false negative based on final nodal status as determined by subsequent SLNB. The cases were then further reviewed to identify pathologic characteristics that were predictive of true negative, false negative, and true positive status.
Results: Both the number of cases in each category along with the relationship to the pathologic parameters is present in Table 1.

Table 1: Relationship of Success of Axillary Ultrasound Pre-screening to Pathologic Parameters

	True neg (n=282)	False neg (n=67)	True pos (n=57)	p value
Average Tumor size (cm)	1.64	2.55	3.56	<0.0001
Number of multifocal cases	45 (16%)	17 (25%)	17 (30%)	<0.05
Average number of positive lymph nodes	NA	3.15	5.82	<0.01
Average size of largest tumor in lymph node (cm)	NA	0.64	1.65	<0.0001

Conclusions: This study provides insight into the pathologic parameters that influence the efficacy of AUS. When features that are classically predictive of nodal involvement by breast carcinoma such as larger tumor size and multifocality are present, there is an increased likelihood of false negative AUS pre-screening over true negative. When present these features should increase the concern for nodal disease, despite negative AUS pre-screening. Furthermore, increased breast tumor size and greater nodal involvement (both by number and largest tumor deposit) are associated with a higher likelihood of true positive AUS pre-screening over false negative. Recent studies suggests that ALND in T1-T2 stage breast cancer does not improve survival in patients with limited nodal disease who are treated with breast-conserving surgery, whole-breast irridation, and adujuvant systemic therapy. As more importance is, therefore, placed on SLNB and other newer screening techniques for metastatic disease, a better understanding of AUS in relation to pathologic parameters is critical.
Category: Breast

Monday, March 19, 2012 2:00 PM

Platform Session: Section B, Monday Afternoon