Axillary nodal burden in primary breast cancer patients with positive pre-operative ultrasound guided fine needle aspiration cytology: Management in the era of ACOSOG Z011

Introduction: Recent years have seen a dramatic shift to more conservative management of the axilla in patients with a positive sentinel lymph node biopsy (SLNB). Identification of nodal disease with positive pre-operative ultrasound guided axillary fine needle aspiration cytology (AUS/FNAC) may represent a higher axillary disease burden mandating an axillary clearance and thus an upfront SLNB may be avoided. The aims of this study were to quantify nodal burden in patients with positive pre-operative AUS/FNAC and identify patients who may have been able to avoid an axillary clearance (ALND) based on ACOSOG Z011 criteria. Methods: A retrospective review of a prospectively maintained database identified patients with positive pre-operative AUS/FNAC between 2007 and 2012. Core biopsies were excluded. Demographic and tumour characteristics were analysed. Eligibility for ACOSOG Z011 criteria was assessed and patients who may have avoided ALND were identified. Results: 432 patients were identified with positive AUS/FNAC. 85 patients were excluded leaving 347 for analysis. Median age was 56 years (22-87), median tumour size was 25 mm (1.5 mm-150 mm) and median tumour pathology was grade 3 (50%) and invasive ductal carcinoma (82%). Median number of nodes removed at ALND was 23 (1-55) with a median number of positive nodes being 4 (1-47). 134 (39%) patients had ≤2 positive nodes identified on ALND making them eligible for the ACOSOG Z011 study. When other ACOSOG Z011 exclusion factors were applied only 27 (7.8%) patients may have avoided ALND. Conclusions: Nodal positivity on AUS/FNAC is associated with higher axillary disease burden. Few patients would satisfy ACOSOG/Z011 criteria and avoid ALND making an upfront SLNB unnecessary.