Abstract
BACKGROUND: Randomized controlled trials show that certain axillary surgical practices can be safely deescalated in older adults with early-stage breast cancer. Hospital volume is often equated with surgical quality, but it is unclear whether this includes performance of low-value surgeries. We sought to describe how utilization of two low-value axillary surgeries has varied by time and hospital volume. METHODS: Women aged ≥ 70 years diagnosed with breast cancer from 2013 to 2016 were identified in the National Cancer Database. The outcomes of interest were sentinel lymph node biopsy (SLNB) in cT1N0 hormone receptor-positive cancer patients and axillary lymph node dissection (ALND) in cT1-2N0 patients undergoing breast-conserving surgery with ≤ 2 pathologically positive nodes. Time trends in procedure use and multivariable regression with restricted cubic splines were performed, adjusting for patient, disease, and hospital factors. RESULTS: Overall, 83.4% of 44,779 women eligible for omission of SLNB underwent SLNB and 20.0% of 7216 patients eligible for omission of ALND underwent ALND. SLNB rates did not change significantly over time and remained significantly different by age group (70-74 years: 93.5%; 75-79 years: 89.7%, 80-84 years: 76.7%, ≥ 85 years: 48.9%; p < 0.05). ALND rates decreased over the study period across all age groups included (22.5 to 16.9%, p < 0.001). In restricted cubic splines models, lower hospital volume was associated with higher likelihood of undergoing SLNB and ALND. CONCLUSIONS: ALND omission has been more widely adopted than SLNB omission in older adults, but lower hospital volume is associated with higher likelihood of both procedures. Practice-specific deimplementation strategies are needed, especially for lower-volume hospitals.