19 Overall survival after surgical staging by lymph node dissection versus sentinel lymph node biopsy in endometrial cancer: a national cancer database study

Objectives To investigate the association between the type of lymph node (LN) assessment and overall survival (OS) in endometrial cancer (EC). Methods Patients with stage I-III EC who underwent a hysterectomy and LN assessment from 2012 to 2015 were identified from the National Cancer Database. Multivariable Cox proportional hazards regression analysis was performed to assess factors associated with OS. Results Of 68,614 patients identified, 64,796 underwent lymphadenectomy (LND) only, 1,777 sentinel lymph node biopsy only (SLN-B), and 2,041 both procedures (SLN-B/LND). On multivariable analysis, SLN-B and SLN-B/LND were not associated with different OS compared to LND (hazard ratio [HR]: 0.92; 95%CI: 0.73–1.17 - HR: 0.91; 95%CI: 0.77–1.07, respectively). Similarly, when stratified by LN status, SLN-B and SLN-B/LND reported similar OS compared to LND, both in negative (HR: 1.03; 95%CI: 0.85–1.26 – HR :0.95; 95%CI: 0.73–1.23, respectively) and positive (HR: 0.92; 95%CI: 0.55–1.54 – HR: 0.76; 95%CI: 0.57–1.03, respectively) LNs. Including only LND with ≥10 pelvic and ≥1 para-aortic LNs removed, no difference in OS was observed between LND and SLN-B or SLN-B/LND in the entire cohort, and in negative or positive LNs. In all analyses, older age, Charlson-Deyo Score ≥2, black race, higher American Joint Committee on Cancer (AJCC) pathologic T stage, grade 3, presence of lymphovascular infiltration, type-2 histology, and absence of chemotherapy or radiation therapy were independently associated with worse OS. Conclusions When compared to SLN-B or SLN-B/LND, LND does not appear to improve OS in EC, even in the presence of LN metastases.