Axillary lymph node dissection (ALND) for breast cancer carries a higher morbidity than sentinel lymph node biopsy. The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial demonstrated that many patients with T1-T2 breast cancer and ≤2 positive lymph nodes can be spared ALND, with favourable long-term results. Despite this, patients with cT1-T2 disease and positive axillary lymph nodes (LN) detected on preoperative ultrasound and fine-needle aspirate (US/FNA) often undergo up-front ALND. The purpose of this study was to examine the proportion of patients with cT1-T2N1 invasive breast cancer who could potentially be spared ALND. 

Patients with cT1-T2N1 primary invasive breast cancer treated with ALND were identified from an institutional database. Patients who received neoadjuvant treatment were excluded. For patients with non-palpable LNs, pre-operative axillary imaging with a positive LN biopsy confirmed N1 status. Patients with ≤2 positive LNs on final pathology were compared for both the palpable and non-palpable groups. 

283 patients underwent ALND for primary T1-T2 invasive breast cancer from 2012-2016.  91 patients met inclusion criteria; 52 (57%) patients had clinically palpable axillary lymphadenopathy, and 39 (43%) had a positive US/FNA.  In the group with palpable lymphadenopathy, 26/52 (50%) had ≤2 positive LNs on final pathology.  In the US/FNA group 17/39 (44%) had ≤2 positive LNs on final pathology.  There was no significant difference between the two.  The positive-predictive value for having a positive US/FNA and >2 LNs on final pathology was 0.56.

Of patients with cT1-T2 tumors who underwent ALND, almost one half (47%) could have potentially been spared an ALND based on ACOSOG Z0011 criteria for nodal burden. These results suggest that upfront ALND in node-positive cT1-T2 breast cancer may lead to overtreatment in some patients. Further study is required to determine possible candidacy for avoiding upfront ALND in the setting of preoperative positive axillary LNs.

Saving the axilla: can we reduce up front axillary lymph node dissection in T1-T2 breast cancers?