Patterns in the Use of Axillary Operations for Patients with Node-Positive Breast Cancer After Neoadjuvant Chemotherapy: A National Cancer Database (NCDB) Analysis.

Background: The American College of Surgeons Oncology Group (ACOSOG) Z1071 and Sentinel Neoadjuvant (SENTINA) trials of sentinel node biopsy for node-positive breast cancer treated with neoadjuvant chemotherapy (NAC) demonstrated false-negative rates that varied on the basis of surgical technique. This study evaluated trends in axillary operations before and after publication of these trials.

Methods: This study analyzed patients from National Cancer Database (NCDB) with clinical T0 through T4, N1 and N2, M0 breast cancer who received NAC from 1 January 2012 to 31 December 2015 and sentinel lymph node biopsy (SNB) or axillary lymph node dissection (ALND). The patients were divided into the following groups: SNB, ALND, and (SNB + ALND).

Results: Of the 32,036 evaluable patients identified in this study. 5565 had SNB, 19,930 had ALND, and 6541 had SNB + ALND. Compared with the ALND group, the SNB group was younger, had more invasive ductal cancers, and had lower clinical T- and N-stage disease (p < 0.001). The patients in the SNB group had a higher rate of estrogen receptor-positive and triple-negative breast cancers, but a lower rate of human epidermal growth factor receptor 2 (HER2)-positive cancer (p < 0.001). The nodal pathologic complete response (PCR) rate, defined as no residual invasive cancer, was 66.5% in the SNB group and 33.1% in the ALND group. Since 2013, the rate of ALND has decreased from 88.7 to 77.1% in both community and academic institutions (p < 0.001).

Conclusion: Since publication of the ACOSOG Z1071 and SENTINA trials, the national rates of ALND in node positive breast cancer treated with NAC have decreased despite reported false-negative SNB rates and lack of prospective outcome data regarding the oncologic safety of ALND omission.