The role of ultrasound-guided fine-needle aspiration of axillary nodes in the staging of breast cancer

Background: As a complement to sentinel node dissection (SLND), we evaluated ultrasound-guided fine-needle aspiration (USFNA) of normal and abnormal axillary nodes in breast cancer patients. We hypothesized that USFNA would be accurate for primary breast tumors larger than 2 cm. Methods: We retrospectively reviewed 68 patients who underwent 69 preoperative USFNAs from 2003 to 2005. The results of 65 preoperative USFNA were compared with the results of SLND or axillary node dissection (ALND) for concordance. Four USFNAs were excluded from analysis because of a complete response to neoadjuvant therapy. We evaluated whether primary tumor features (histology, size, grade, vascular invasion, estrogen/progesterone receptor status and Her-2-neu status) predicted concordance of USFNA results and the final lymph node pathology. Results: Of 65 axillae analyzed, 39 (60%) were positive, four (6%) were non-diagnostic, and 22 (34%) were negative by USFNA. USFNA had 89% sensitivity, 100% specificity, and 100% positive predictive value (PPV) in patients with palpable or ultrasonographically suspicious nodes. USFNA sensitivity dropped significantly for nonpalpable, ultrasonographically normal nodes (54%), while specificity and PPV remained 100%. None of the primary tumor features predicted concordance of USFNA and SLND/ALND. Conclusions: USFNA of axillary nodes has a high specificity and PPV in clinically or radiologically suspicious nodes. Sensitivity of USFNA is low for nodes of normal appearance, but positive USFNA may allow definitive management of the axilla without a SLND. Thus, USFNA of normal appearing nodes might be beneficial in cases where decisions regarding neoadjuvant chemotherapy would be affected by the results.