Impact of sentinel lymph node mapping on survival in patients with high-risk endometrial cancer in the early stage: A matched cohort study.

Objective: The aim of this study was to compare patient survival using sentinel lymph node (SLN) procedure and pelvic lymphadenectomy for stating early-stage high risk endometrial cancer.

Methods: Patients who underwent surgery for early-stage high risk endometrial cancer between 2010 and 2017 were extracted from the incidence registry of the SEER program. We identified patients who underwent SLN mapping. Patients who initially underwent pelvic lymphadenectomy were selected as the comparison group. One-to-one matching was performed according to age, ethnicity, histology, extension and grade. The primary outcome was disease-specific survival. The secondary outcome was overall survival.

Results: A total of 326 patients who underwent SLN mapping and 326 who underwent pelvic lymphadenectomy initially were included in the study. The three-year analysis did not find a significant difference between the SLN and lymphadenectomy groups on disease-specific survival probability (88.2% vs 82.7, P = 0.07) and on overall survival probability (82.7% vs 78.2%, P = 0.57). Patients who underwent SLN mapping had a lower mean number of lymph nodes removed (mean 3 vs 16, P < 0.001) and there was a higher rate of patients with positive pelvic lymph nodes (18% vs 14%, P = 0.04). Following adjustment for confounding factors, disease-specific survival did not vary according to the lymph node intervention performed (P = 0.056), but the SLN group had better overall survival than those in the lymphadenectomy group (P = 0.047).

Conclusion: The SLN technique was not associated with poorer disease-specific survival than pelvic lymphadenectomy even after adjustment. These results suggest that SLN is an acceptable and safe procedure in surgical staging for early-stage high-risk endometrial cancer.