Nodal Metastasis Risk in Endometrioid Endometrial Cancer

Abstract

OBJECTIVE: To estimate the risk for nodal metastasis in women with endometrial cancer based on uterine characteristics on pathology. METHODS: From a study of staging for uterine cancer, women were identified as being at low risk for nodal metastasis based on three specific criteria on final pathology reports: 1) less than 50% invasion, 2) tumor size less than 2 cm, and 3) well or moderately differentiated endometrioid histology. If the uterine specimen did not meet all three criteria, it was viewed as high risk for nodal metastasis. RESULTS: Nine hundred seventy-one women were included in this analysis. Approximately 40% (or 389 of 971) of patients in this study were found to be at low risk, with a rate of nodal metastasis of only 0.8% (3 of 389; exact 95% confidence interval [CI] 0.16-2.2). No statistical differences in median age, body mass index, race, performance status, missing clinical data, or open or minimally invasive techniques were found among the patients with and without nodal metastases. Patients with high-risk characteristics of their uterine specimens compared with those with low-risk characteristics have 6.3 times the risk of nodal metastasis (95% CI 1.67-23.8, P=.007). CONCLUSION: Low-risk endometrioid uterine cancer criteria may be used to help guide treatment planning for reoperation in patients with incomplete surgical staging information. LEVEL OF EVIDENCE: II.