The characteristics of isolated para-aortic lymph node metastases in endometrial cancer and their prognostic significance

BACKGROUND: The aim of this study was to clarify the features and prognostic significance of isolated para-aortic lymphatic metastasis of endometrial cancer. METHODS: A retrospective study of patients with stage IIIC endometrial cancer was performed based on the Surveillance, Epidemiology, and End Results (SEER) database. A total of 2767 patients were divided into three groups according to the lymphatic metastasis patterns: isolated pelvic lymphatic metastasis, isolated para-aortic lymphatic metastasis and dual lymphatic metastasis. The clinic-pathological characteristics and prognosis of patients were compared among the three groups. RESULT: The proportion of patients with isolated para-aortic lymphatic metastasis was 13.70%. Patients with isolated pelvic lymphatic metastasis or isolated para-aortic lymphatic metastasis shared similar histological characteristics, except that patients with isolated para-aortic lymphatic metastasis had a lower proportion of tumors over 5 cm in diameter than patients with isolated pelvic lymphatic metastasis (35.1% versus 45.7%, p = 0.001). Compared with patients with dual lymphatic metastasis, isolated para-aortic lymphatic metastasis was more common in patients with endometrioid tumors (78.6% versus 67.3%, p < 0.001), grade 1–2 cancers (53.3% versus 36.3%, p < 0.001) and negative peritoneal cytology (76.2% versus 61.1%, p < 0.001). Dual lymphatic metastasis was an independent predictive factor for the poor outcomes of patients at stage IIIC. However, in stage IIIC endometrioid tumors, patients with isolated pelvic lymphatic metastasis and those with isolated para-aortic lymphatic metastasis shared similar prognosis. Patients at stage IIIC with nonendometrioid tumors and patients at stage IV could not be further divided into subgroups according to lymphatic metastasis patterns in terms of prognosis. CONCLUSION: Endometrioid patients with isolated pelvic lymphatic metastasis and isolated para-aortic lymphatic metastasis share similar clinical pathological characteristics and prognoses.