Findings of the ACOSOG Z11 trial have proven controversial, leaving physicians divided over which patients with positive sentinel lymph nodes (+SLNs) benefit from axillary lymph node dissection (ALND). Our institution reviewed our own experience with Z11-eligible patients who did not undergo ALND and explored factors that predict for +LNs on ALND following 1–2 +SLNs to determine which patients benefit from adjuvant therapy.

All breast cancer pathology reports from our institution containing the word “sentinel” between 7/1998 and 12/2001 were reviewed. We obtained follow-up information on patients meeting Z11 eligibility criteria that did not undergo ALND. We also compared pathological characteristics between patients with 1–2 +SLNs and +LNs on ALND to those with no further +LNs.

Of the 432 pathology reports reviewed, 38 were from patients meeting Z11-criteria that did not undergo ALND. At a median follow-up of 11.9yr, these patients had 5yr overall survival (OS) of 93.3% and 10yr OS of 79.3%. No patient had recurrent disease in the axilla. Of the 80 patients with 1–2 +SLNs who underwent ALND, tumors with +LNs on ALND were generally larger, non-ductal histology, more likely to be ER+, and PR+, and less likely to be Her2+.

Our institution’s 5yr OS (93.3%) for Z11-eligible patients closely resembled those from the Z11 trial (92.5%) and our 10yr data provide evidence of what to expect for Z11-enrolled patients on continued follow-up. Larger tumor, non-ductal, ER+, PR+, and Her2- were predictive for further +LNs on ALND which may reflect surgical bias.