Overall Survival After Sentinel Lymph Node Biopsy Versus Axillary Lymph Node Dissection in Patients With Three Recorded Positive Nodes: A National Cancer Database Analysis.

BACKGROUND: Randomized trials support omission of completion axillary lymph node dissection (ALND) in selected patients with 1 or 2 positive sentinel lymph nodes, but evidence for 3 positive sentinel nodes is limited. We evaluated the association between the extent of axillary surgery and overall survival (OS) in patients with 3 recorded positive nodes. PATIENTS AND METHODS: Female patients with cT1-2N0M0 unilateral invasive breast cancer who underwent breast-conserving surgery between 2012 and 2016 and had 3 positive lymph nodes were identified in the National Cancer Database. The sentinel lymph node biopsy (SLNB) group had 3 positive sentinel nodes without completion ALND; the ALND group had 3 total positive nodes after completion dissection. The primary outcome was OS. RESULTS: Among 700 patients, 217 (31%) underwent SLNB alone and 483 (69%) underwent completion ALND. Thirty-six deaths occurred. Irradiation to breast/chest-wall lymph-node regions was recorded in 59.4% and 57.6%, respectively (P = .56), although specific nodal basins were unavailable. At a median follow-up of 51.6 months, 5-year OS was similar between the SLNB and ALND groups (94.3% vs. 93.8%, P = .85). Omission of ALND was not significantly associated with OS after adjustment (adjusted HR 0.94, 95% CI 0.44-2.01, P = .85). Hormone receptor-negative disease and omission of adjuvant therapy were independently associated with worse survival. CONCLUSION: Omission of ALND was not associated with inferior OS in patients with 3 positive lymph nodes. These findings support prospective evaluation and should not be interpreted as evidence that all additional axillary treatment can be omitted.