Introduction The therapeutic effect of para-aortic lymphadenectomy in early-stage high-grade endometrial cancer remains controversial. In this study, we investigated whether combined pelvic and para-aortic lymphadenectomy has a survival benefit compared to pelvic lymphadenectomy alone in patients with pathologically diagnosed FIGO stage I-II grade 3 endometrioid and non-endometrioid endometrial cancers.

Methods Weretrospectively reviewed themedical records of 281 patientswith histologically confirmed FIGO stage I-II grade 3 endometrioid and non-endometrioid endometrial cancers who underwent pelvic lymphadenectomy alone or combined pelvic and para-aortic lymphadenectomy in staging surgery at two tertiary centers in Korea and Taiwan. Prognostic factors to predict outcomes in these cases were also analyzed.

Results Among 281 patients, 144 underwent pelvic lymphadenectomy alone and 137 underwent combined pelvic and para-aortic lymphadenectomy. Within amedian follow-up of 45 months, there was no significant difference in recurrence-free survival (RFS) and overall survival (OS) between the two groups. In multivariable analysis, age at diagnosis ≥60 years (HR = 2.20, 95% CI 1.25–3.87, p = 0.006) and positive lymph-vascular space invasion (LVSI) (HR = 2.79, 95% CI 1.60–4.85, p < 0.001) were associated with worse RFS, and only non-endometrioid histology was associated with worse OS (HR=3.18, 95% CI 1.42–7.12, p=0.005). In further subgroup analysis, beneficial effects of combined pelvic and para-aortic lymphadenectomy on RFS and OS were not observed.

Conclusion/Implications In this study, combined pelvic and para-aortic lymphadenectomy could not improve survival compared to pelvic lymphadenectomy alone in patients with FIGO stage I-II grade 3 endometrioid and nonendometrioid endometrial cancers. Therefore, para-aortic lymphadenectomy may be omitted for these cases.