Role of axillary ultrasound, magnetic resonance imaging, and ultrasound-guided fine-needle aspiration biopsy in the preoperative triage of breast cancer patients.

Purpose: Roughly two-thirds of early breast cancer cases are associated with negative axillary nodes and do not benefit from axillary surgery at all. Accordingly, there is an ongoing search for non-surgical staging procedures to avoid lymph-node dissection or sentinel node biopsy (SNB). Non-invasive imaging techniques with very high sensitivity (Se) and negative predictive value (NPV) could eventually replace SNB. We aimed to establish the role of axillary US and MRI, alone or in combination, associated with ultrasound-guided fine-needle aspiration biopsy (US-FNAB) in the prediction of axillary node involvement.

Methods/patients: Between January 2003 and September 2015, we included 1505 of the 1538 breast cancer patients attending our centres. All patients had been referred from a single geographical area. Axillary US, magnetic resonance imaging and ultrasound-guided fine-needle aspiration biopsy (US-FNAB) were performed if required.

Results: 1533 axillary US examinations and 1351 axillary MRI studies were analyzed. For axillary US, Se, Specificity (Sp), Positive Predictive Value (PPV), and NPV were 47.5, 93.6, 82.5, and 73.8%, respectively. For axillary MRI, corresponding values were 29.8, 96.6, 84.9, and 68.4%. When both tests were combined, Sp and PPV slightly improved over individual tests alone. US-FNAB showed a 100% Sp and PPV, with a Se of 80%.

Conclusion: We may confidently state that axillary US and US-FNAB have to be included in the preoperative work-up of breast cancer patients.