Introduction Objective: This study aimed to determine whether the number of resected pelvic lymph nodes (PLNs) affects the prognosis of endometrial cancer patients at post-operative risk of recurrence.

Methods JGOG2043 was a trial to assess the efficacy of three different chemotherapeutic regimens as adjuvant therapy in endometrial cancer patients with post-operative recurrent risk. Two hundred fifty patients who underwent pelvic lymphadenectomy alone in JGOG2043 were analyzed retrospectively. The number of resected and positive nodes and other clinicopathologic risk factors for survival were retrieved.

Results There were 167 patients in the group with 20 or more PLNs removed, while 83 patients had less than 20 PLNs removed. There was no significant difference in patients’ backgrounds between the two groups, and the rate of lymph node metastasis was not significantly different (28.1% vs. 24.1%, P=0.49). There was a trend toward fewer pelvic recurrences in the group with 20 or more PLNs removed (3.5% vs. 9.6%, P=0.0502). Although Kaplan-Meier analysis showed no significant difference in survival rates between 20 or more and less than 20 groups (5-year OS: 90.3% vs. 84.3%, P=0.20), multivariate analysis revealed that the number of resected nodes is one of the independent risk factors (HR, 0.49; 95%CI, 0.24–0.99; P=0.048), as well as surgical stage, high-risk histology, and advanced age for overall survival.

Conclusion/Implications Resection of 20 or more nodes in the pelvic region was associated with improved pelvic control and better survival outcomes in endometrial cancer patients who underwent pelvic lymphadenectomy alone at risk of recurrence treated with adjuvant chemotherapy.