Prognostic impact of the number of resected pelvic nodes in endometrial cancer: Japanese Gynecologic Oncology Group Study JGOG2043 post hoc analysis

Objective: This study aimed to determine whether the number of resected pelvic lymph nodes (PLNs) affects the prognosis of endometrial cancer (EC) patients at post-operative risk of recurrence. Methods: JGOG2043 was a randomized controlled trial to assess the efficacy of three chemotherapeutic regimens as adjuvant therapy in EC patients with post-operative recurrent risk. A retrospective analysis was conducted on 250 patients who underwent pelvic lymphadenectomy alone in JGOG2043. The number of resected and positive nodes and other clinicopathologic risk factors for survival were retrieved. Results: There were 83 patients in the group with less than 20 PLNs removed (group A), while 167 patients had 20 or more PLNs removed (group B). There was no significant difference in patients' backgrounds between the two groups, and the rate of lymph node metastasis was not significantly different. There was a trend toward fewer pelvic recurrences in group B compared with group A (3.5% vs. 9.6%; p=0.050). Although Kaplan-Meier analysis showed no statistically significant difference in survival rates between the two groups (5-year overall survival [OS]=90.3%vs. 84.3%; p=0.199), multivariate analysis revealed that resection of 20 or more nodes is one of the independent prognostic factors (hazard ratio=0.49; 95% confidence interval=0.24-0.99; p=0.048), as well as surgical stage, high-risk histology, and advanced age for OS. Conclusion: Resection of 20 or more PLNs was associated with improved pelvic control and better survival outcomes in EC patients at risk of recurrence who underwent pelvic lymphadenectomy alone and were treated with adjuvant chemotherapy.