Multicenter study comparing oncologic outcomes after lymph node assessment via a sentinel lymph node algorithm versus comprehensive pelvic and paraaortic lymphadenectomy in patients with serous and clear cell endometrial carcinoma.

Objectives: To compare survival after nodal assessment using a sentinel lymph node (SLN) algorithm versus comprehensive pelvic and paraaortic lymphadenectomy (LND) in serous or clear cell endometrial carcinoma, and to compare survival in node-negative cases.

Methods: Three-year recurrence-free survival (RFS) and overall survival were compared between one institution that used comprehensive LND to the renal veins and a second institution that used an SLN algorithm with ultra-staging with inverse-probability of treatment weighting (IPTW) derived from propensity scores to adjust for covariate imbalance between cohorts.

Results: 214 patients were identified (118 SLN cohort, 96 LND cohort). Adjuvant therapy differed between the cohorts; 84% and 40% in the SLN and LND cohorts, respectively, received chemotherapy ± radiation therapy. The IPTW-adjusted 3-year RFS rates were 69% and 80%, respectively. The IPTW-adjusted 3-year OS rates were 88% and 77%, respectively. The IPTW-adjusted hazard ratio (HR) for the association of surgical approach (SLN vs LND) with progression and death was 1.46 (95% CI: 0.70-3.04) and 0.44 (95% CI: 0.19-1.02), respectively. In the 168 node-negative cases, the IPTW-adjusted 3-year RFS rates were 73% and 91%, respectively. The IPTW-adjusted 3-year OS rates were 88% and 86%, respectively. In this subgroup, IPTW-adjusted HR for the association of surgical approach (SLN vs LND) with progression and death was 3.12 (95% CI: 1.02-9.57) and 0.69 (95% CI: 0.24-1.95), respectively.

Conclusion: OS was not compromised with the SLN algorithm. SLN may be associated with a decreased RFS but similar OS in node-negative cases despite the majority receiving chemotherapy. This may be due to differences in surveillance.