Should Palpable Nodes Be Exclusionary in Patients Who Are Otherwise Candidates for ACOSOG Z0011-Type Trials?

Palpable nodes were exclusionary in American College of Surgeons Oncology Group (ACOSOG) Z0011, while SINODAR-ONE excluded those with positive axillary nodes by palpation and ultrasound. To determine whether clinical nodal status should be exclusionary in those fulfilling pathologic criteria for ACOSOG Z0011 and similar trials, this study analyzed the accuracy and implications of clinical nodal positivity.

Patients ≥ 18 years old with cT1-T2, cN0-cN1, M0 breast cancer were identified in the National Cancer Database between 2004 and 2019. Subset characteristics of cN1 and cN0 were compared with respect to final pathologic nodal status and overall survival (OS).

Of 57,823 patients identified, 77.0% were cT1 and 23.0% were cT2. Of the 93.9% of patients who were staged as cN0, 16.7% were pN1; of the remaining 6.1% staged as cN1, 9.6% were found to be pN0. Among cN1/pN0 patients, 14.9% underwent axillary dissection without sentinel node biopsy. There was no difference in adjusted OS for patients staged as cN0 versus cN1 who were found to be pN1 (HR 1.13, 95% CI 0.93-1.37, p = 0.22), a finding that persisted on subset analysis in those with two positive nodes (HR 0.91, 95% CI 0.62-1.33, p = 0.63).

Clinical nodal stage does not affect OS in pN1 patients. Clinical nodal assessment can both overstage patients and result in unnecessary axillary surgery. These data suggest that cN1 patients who are otherwise candidates for a Z0011-like paradigm should still be considered eligible. Their final candidacy should be determined by surgical lymph node pathology and not preoperative clinical status.