Patterns of completion axillary dissection for patients with cT1‐2N0 breast cancer undergoing total mastectomy with positive sentinel lymph nodes

Abstract

AbstractBackground and ObjectivesThe ACOSOGZ0011 trial found that overall survival (OS) for patients with 1–2 positive nodes undergoing sentinel lymph node biopsy‐alone (SLNB) was noninferior to completion axillary lymph node dissection (ALND), but excluded patients undergoing mastectomy. Our study examined patterns of ALND and its relationship with OS for SLNB‐positive patients undergoing mastectomy.MethodsThe National Cancer Database was queried (2010–2017) for patients with cT1‐2N0 breast cancer undergoing mastectomy with positive sentinel lymph nodes. Clinical data were compared.ResultsOf 20 001 patients, 11 574 (57.9%) underwent SLNB + ALND, and 8427 (42.1%) had SLNB‐alone. The SLNB + ALND group had more positive nodes (mean 2.6 vs. 1.3, p < 0.001) and more frequently received nodal radiation (33.4% vs. 28.9%, p < 0.001). Patients diagnosed in later years were less likely to undergo ALND (2010: reference; 2017: odds ratio: 0.29, 95% confidence interval [CI]: 0.25–0.33, p < 0.001). ALND (hazard ratio [HR]: 0.97, 95% CI: 0.89–1.06, p = 0.49) and nodal radiation (HR: 0.92, 95% CI: 0.83–1.02, p = 1.06) were not independently associated with OS. Propensity‐score matched 5‐year OS was similar (SLNB + ALND: 90.9% vs. SLNB‐alone: 90.3%, p = 0.65).ConclusionFor patients undergoing mastectomy for cT1‐2N0 breast cancer with positive SLNB, SLNB‐alone was common and increased over time. Axillary radiation was not routinely delivered in the SLNB‐alone group. Completion ALND and nodal radiation were not associated with improved survival.