EPV093b/#769 Paradigm shift to sentinel lymph node biopsy in endometrial cancer surgery: recent U.S. trends

Abstract

<h3>Objectives</h3> This study examined the population-level uptakes and outcomes of sentinel lymph node (SLN) biopsy for early endometrial cancer. <h3>Methods</h3> This retrospective observational study queried the Surveillance, Epidemiology, and End Results Program, examining 83,139 women with endometrial cancer who underwent primary hysterectomy with lymph node evaluation for T1 disease from 2003–2018. Main outcome measures were (i) temporal trends and patient characteristics in utilization of SLN biopsy, and (ii) endometrial cancer-specific mortality associated with SLN biopsy. <h3>Results</h3> The utilization of SLN biopsy increased significantly from 0.2% to 29.7% from 2005–2018 with robust increase after 2016 (P&lt;0.001; top-panel). The uptake of SLN biopsy was higher for endometriod histology (0.3% to 31.6% between 2005–2018) versus non-endometriod histology (0.6% to 21.0% between 2006–2018)(both, P&lt;0.001). In a multivariable analysis, recent year surgery, endometrioid histology, well-differentiated tumors, T1a disease, and smaller tumor size remained independent characteristics for SLN biopsy use (all, P&lt;0.05). Performance of SLN biopsy was not associated with increased endometrial cancer-specific mortality compared to lymphadenectomy in endometrioid hystology (subdistribution-HR 0.96, 95%CI 0.82–1.1; bottom-panel) and non-endometriod histology (subdistribution-HR 0.85, 95%CI 0.69–1.0) in propensity score weighted models. In low-risk endometrial cancer, the increase in recent SLN biopsy resulted in 15.3 percent point increase in the surgical nodal evaluation by 2018 (expected versus observed rates, 37.8% versus 53.1%). <h3>Conclusions</h3> The landscape of surgical nodal evaluation is shifting from lymphadenectomy to SLN biopsy in early endometrial cancer. Effects of SLN biopsy-based surgical treatment on endometrial cancer survival warrants further confirmation.