National Trend of Axillary Management in Clinical T3/T4 N0 Patients Having Breast Conserving Therapy.

BACKGROUND: The ACOSOG Z0011 trial has essentially eliminated axillary lymph node dissection (ALND) in breast conserving therapy (BCT) patients with clinical T1/T2 and 1-2 positive sentinel lymph nodes (SLNs). Currently, ALND is recommended for positive SLNs unless ACOSOG Z0011 criteria are applicable. We aimed to assess the national trends and axillary management before and after the publication of ACOSOG Z0011 for larger tumors. METHODS: An IRB-approved study evaluated the National Cancer Database from 2006 to 2016. Women with clinical T3/T4, N0 who otherwise fit ACOSOG Z0011 criteria were included. Neoadjuvant systemic therapy or known nodal disease was excluded. Clinicopathologic data were compared between two timeframes based on ACOSOZ Z0011 publication and by axillary management. Patients were categorized into SLNB alone (1-5 lymph nodes examined) and ALND (≥10 lymph nodes examined) groups. RESULTS: A total of 230 women fit inclusion criteria, of whom 36% underwent ALND. ALND use decreased from 54% in 2006 to 14% in 2016 (P < 0.01). Comparing ALND to SLNB alone within the pre-Z0011 era, comprehensive community cancer programs had higher proportions of ALND, whereas academic centers had higher rates of SLND alone (P = 0.03). Comparing similar axillary management between eras, SLNB-alone patients in the post-Z0011 era had higher pT and pN stages, were less likely to be Her2 positive, and were more likely to receive systemic treatment. CONCLUSIONS: There is a national trend to forgo ALND in women who have tumors larger than those included in the Z0011 criteria without any clear clinicopathologic indications.