Outcomes of sentinel lymph node mapping for patients with FIGO stage I endometrioid endometrial carcinoma.

OBJECTIVE: Investigate the overall survival of patients with FIGO stage I endometrioid endometrial carcinoma who underwent sentinel lymph node biopsy (SLNBx). METHODS: Patients diagnosed between 2012 and 2015 with pathological stage I endometrioid endometrial carcinoma who underwent minimally invasive hysterectomy and had at least one month of follow-up were identified in the National Cancer Database (NCDB). Patients who underwent SLNBx or systematic lymphadenectomy (LND) (defined as at least 20 lymph nodes removed) were selected. Overall survival (OS) was evaluated following generation of Kaplan-Meier curves and compared with the log-rank test. A Cox model was constructed to evaluate survival after controlling for confounders. RESULTS: A total of 13,010 patients with endometrioid endometrial carcinoma who met the inclusion criteria were identified; 9861 (75.8%) and 3149 (24.2%) patients had systematic LND and SLNBx, respectively. Patients who had LND were more likely to receive radiation therapy (27.4% vs 19.3%, p < 0.001) and chemotherapy (13% vs 8.7%, p < 0.001) compared to those who had SLNBx. After controlling for patient age, race, insurance status, depth of myometrial invasion, tumor grade, tumor size, presence of lymph-vascular invasion and receipt of radiation therapy, the performance of SLNBx was not associated with worse survival (HR: 0.99, 95% CI: 0.80, 1.21). For high-intermediate risk patients (based on GOG-99 criteria) after controlling for confounders, performance of SLNBx was not associated with worse survival (HR: 1.07, 95% CI: 0.80, 1.44). For intermediate risk patients who did not receive external beam radiation therapy or chemotherapy after controlling for confounders, performance of SLNBx was not associated with worse survival (HR: 1.58, 95% CI: 0.94, 2.65). CONCLUSIONS: SLNBx had no negative impact on the survival of patients with FIGO stage I endometrioid endometrial carcinoma who undergo hysterectomy.