Consequences of Axillary Ultrasound in Patients with T2 or Greater Invasive Breast Cancers

Background. Axillary ultrasound (AUS) with needle biopsy is used to detect metastasis in patients with invasive breast cancers. Our hypothesis is that preoperative AUS significantly reduces sentinel node biopsy (SLNB) use in patients with invasive breast tumors >2 cm upon clinical examination. Methods. A single-institution database of patients with breast cancer and AUS was reviewed. Patients with incomplete records, clinical tumor <2 cm, or postoperative AUS were excluded. A control cohort of non-AUS patients with clinical T2 (cT2) or greater disease was identified. Clinicopathologic data were collected. Simple Kappa coefficient and chi-square statistical analyses were performed. Results. AUS was performed in 153 patients vs. 370 controls. Of AUS patients, 112 (73.2%) had cT2 disease vs. 272 (73.5%) controls. Median AUS patient age was 53.7 (range, 22.8-85.8) years vs. 53.8 (range, 26.7-91.6) years; median pathologic tumor was 3.8 (range, 1.0-20.0) cm in AUS patients vs. 2.5 (range, 0.1-11.0) cm. Among AUS patients, 78% had needle biopsy; 85 of 120 (70.8%) were positive. Sixty-eight patients had SLNB: 33 after negative AUS and 35 after negative needle biopsy. Twenty-three SLNB (37.3%) were positive; 15 of 33 after negative AUS and 8 of 35 after a negative needle biopsy. Axillary dissection was performed in 102 of 153 vs. 225 of 370 controls. Sensitivity and specificity of AUS was 86.2% and 40.5%. Sensitivity of AUS plus needle biopsy was 89.3% with 100% specificity. Neoadjuvant chemotherapy was given to 49.7% of AUS patients. AUS reduced costs by more than $4,000 per patient. Conclusions. AUS reduces SLNB use and affects treatment in patients with cT2 or greater breast cancer. Routine AUS should be considered in this population.