A patient group at negligible risk of para-aortic lymph node metastasis in endometrial cancer.

Objective: The objective of this study was to identify a group at negligible risk of para-aortic lymph node metastasis (LNM) in endometrial cancer and its presumed prognosis.

Methods: We enrolled 555 patients with endometrial cancer who underwent preoperative endometrial biopsy, pelvic magnetic resonance imaging, and determination of serum cancer antigen (CA)125, and surgical treatment including lymphadenectomy. Three risk factors for LNM confirmed in previous reports were grade 3/non-endometrioid histology, large tumor volume, and a high CA125 value. Pelvic LNM rate, para-aortic LNM rate, and 5-year overall survival rate were assessed in four groups according to the number of these risk factors.

Results: LNM was noted in medical records of 74 patients (13.3%). Of 226 patients in the no risk factor group, pelvic LNM was noted in the medical records of five (2.2%), but no para-aortic LNM was noted. The 3-year/5-year survival rates in the no risk factor group were 97.2/96.6%, with a median follow-up period of 65.5 months. Of 186 patients in the one risk factor group, 21 (11.2%) had pelvic LNM. Of 113 patients undergoing para-aortic LN dissection in the one risk factor group, six (5.3%) had para-aortic LNM.

Conclusion: Patients with grade 1/2 histology based on endometrial biopsy, small tumor volume assessed by magnetic resonance imaging, and low CA125 value are supposed to have negligible risk of para-aortic LNM. In such patients, the para-aortic region might not be considered as a target to be assessed by staging procedure.