Incidence of metastasis in circumflex iliac nodes distal to the external iliac nodes in intermediate- and high-risk endometrial cancer

ObjectiveThe aim of this study was to elucidate the incidence of metastasis in circumflex iliac nodes distal to the external iliac nodes (CINDEIN), which are also called suprainguinal nodes, in intermediate- and high-risk endometrial cancer. Removal of these nodes needs to be discussed from the viewpoint of patient's quality of life because removal of CINDEIN is strongly related to lower extremity lymphedema.MethodsA retrospective chart review was carried out for 508 patients with intermediate- and high-risk endometrial cancer who were included in this study. We identified patients with lymph node metastasis. Lymph node sites were classified into four groups: (1) CINDEIN, (2) external iliac nodes, (3) Group A consisting of circumflex iliac nodes to the distal obturator nodes, internal iliac nodes, obturator nodes, cardinal ligament nodes (including deep obturator nodes), and sacral nodes, and (4) Group B consisting of common iliac nodes and para-aortic nodes. Logistic regression analysis was used to select risk factors for CINDEIN metastasis.ResultsIn an analysis of 508 patients with intermediate- and high-risk disease, CINDEIN metastasis was found in fourteen (2.8%) of the patients. Multivariate analysis confirmed that high-risk histology (OR = 5.7, 95% CI = 1.2–16.1) and Group A node metastasis (OR = 9.7, 95% CI = 2.9–31.4) were independent risk factors for CINDEIN metastasis. None of the patients with G1 endometrioid adenocarcinoma had CINDEIN metastasis. Three (2.5%) of the patients with G2 endometrioid adenocarcinoma had CINDEIN metastasis and all of these three patients had other pelvic node metastasis.ConclusionRemoval of CINDEIN can be eliminated in patients with G1 endometrial cancer and patients with G2 endometrial cancer who have no pelvic node metastasis.

Research highlights
► Incidence of metastasis in circumflex iliac nodes (CINDEIN) in endometrial cancer.
► Removal of CINDEIN can be eliminated in patients with G1/G2 endometrial cancer.
► Preservation of CINDEIN might reduce the incidence of lower-extremity lymphedema.