Variation in Deescalated Axillary Surgical Practices in Older Women with Early-Stage Breast Cancer.

Abstract

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. 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. 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. 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.