A comparative analysis of axillary nodal burden in ultrasound/biopsy positive axilla vs ultrasound negative sentinel lymph node biopsy positive axilla.

Abstract

Axillary Ultrasound (AUS) is now performed as a protocol in every newly diagnosed breast cancer in most European countries. It is an inexpensive and sensitive tool in hands of a trained operator. All AUS negative patients undergo Sentinel Lymph Node Biopsy (SLNB), while AUS positive patients bypass SLNB and undergo axillary nodal clearance (ANC) as a standard protocol. We wish to analyse these two groups to see if ANC can be foregone in these patients. To compare and analyse the axillary disease burden in early breast cancer patients, with positive axilla, detected by AUS+ Biopsy versus those patients with normal axillary ultrasound or negative axillary biopsy that underwent ANC due to positive SLNB. A retrospective review of all patients who underwent axillary lymph node clearance following histologically confirmed positive ultrasound (US) axilla (year 2009-2014) was performed and was compared with data collected for patients with USG negative but SLNB (OSNA- One Step Nucleic Acid Amplification) positive axilla. Axillary clearances performed for positive US axilla yielded significantly more positive lymph nodes than SLNB/OSNA positive axilla (p =0.00496). These patients also had larger primary tumours (median 33mm versus 21mm, p =0.01242) of a higher grade. Almost half of the patients in AUS positive group (49%) had high axillary nodal burden (>4 LNs). This is in great contrast with AUS negative, SLNB/OSNA positive group where 82.7% of patients had <4 positive nodes with more than half patients (51.7%) having no further positive nodes in their final histopathology specimen. ANC should be a standard protocol in AUS positive patients as they invariably have high axillary disease burden while ANC can be omitted in case of select AUS negative and SLNB patients. However, further studies with more subjects may be require to substantiate the findings.