Axillary ultrasound and Fine-Needle Aspiration Cytology in the preoperative staging of axillary node metastasis in breast cancer patients.

OBJECTIVE: A prospective observational clinical study was undertaken to assess the accuracy of preoperative Axillary Ultrasound (AUS) plus Fine-Needle Aspiration Cytology (FNAC) as well as and its clinical utility, that is the capacity of the information supplied by the test to guide the clinical decision-making.

MATERIALS AND METHODS: from January 2013 to August 2015, 400 female patients with pT1-3 cN0 operable breast cancer underwent AUS with FNAC at the Breast Unit of the "IRCCS San Martino-IST" in Genoa (Italy).

RESULTS: 127 out of 400 patients (31.7%) had axillary lymph node metastases; in 69 out of 127 node-positive patients (54.3%) AUS detected at least one abnormal lymph node, and in 56 out of 127 patients (44.1%) the abnormal sonographic pattern of the lymph node was coupled with a positive FNAC finding. No false-positive finding by both AUS-alone or combined AUS/FNAC was observed. AUS-alone had sensitivity of 54.3% (69/127), specificity of 100% (273/273), PPV of 100% (69/69), NPV of 82.5% (273/331), and accuracy of 85.5% (342/400). Combined AUS/FNAC had sensitivity of 44.1% (56/127), specificity of 100% (273/273), PPV of 100% (56/56), NPV of 79.4% (273/344), and accuracy of 82.2% (329/400).

CONCLUSIONS: AUS-alone or combined AUS/FNAC had a high accuracy rate coupled with a more than satisfactory efficiency due to their low costs and easy access for the preoperative staging of the axilla. Notably, AUS-alone might be suggested for the preoperative staging of patients with early stage breast cancer because FNAC did not increased the specificity but reduced the sensitivity of the technique. Patients with negative findings might undergo either SLNB or close observation while waiting for the definitive results of ongoing SOUND randomized clinical trial.