Axillary ultrasound-guided core biopsy in breast cancer: identifying higher nodal burden and more aggressive clinicopathological characteristics

Background: Patients with sentinel lymph node (SLN) metastases may not require axillary lymph node dissection (ALND) but it remains unclear if patients with a positive ultrasound-guided axillary core biopsy (ACB) would satisfy such criteria. Aims: The aim of this study was to assess if breast cancer patients with a positive pre-operative ACB have more aggressive tumour characteristics/higher axillary nodal burden compared to those with a positive SLN. Methods: Data was extracted from a prospectively maintained breast cancer database between 2012 and 2015. Patients who underwent ALND after either positive ACB or SLN were included and tumour characteristics/nodal burden were compared. Results: One hundred eighty patients underwent ALND, 125/180 after positive ACB and 55/180 after positive SLNB. Patients with positive ACB were more likely to undergo mastectomy (chi-square test; p = 0.03) and have higher tumour grades (Mann-Whitney test; p < 0.01) compared to the SLNB group. Median positive nodes excised during ALND were 2 (1–22) and 1 (1–11) for ACB and SLNB groups respectively (p < 0.001). Fifty-six patients received neoadjuvant chemotherapy (NCT). Of 72/125 patients in the ACB group not receiving NCT, the median number of positive nodes was 4 (range, 1–22). Ten patients within the ACB group satisfied ACOSOG Z011 criteria. Conclusion: Breast cancer patients with a positive ACB are more likely to have aggressive tumour characteristics and higher nodal burden compared to those identified as having axillary nodal disease on SLNB, which may affect surgical decision making.