Objective The aim of this study was to assess whether lymphovascular space invasion (LVSI) and nodal status provide adequate prognostic information in comparison with the entire set of traditional prognostic factors in intermediate- and high-risk endometrial cancer patients treated and staged with primary surgery and adjuvant radiotherapy.

Methods Three hundred twenty-four previously untreated high-intermediate- and high-risk endometrial cancer patients with FIGO (International Federation of Gynecology and Obstetrics) stage I to IIIC; endometrioid, serous, or clear cell histology; diagnosed between November 1995 and December 2006; who presented to Peter MacCallum Cancer Centre for adjuvant radiotherapy were included in these analyses. All traditionally recognized prognostic factors and newly created 4 pairs of combination of LVSI and nodal status were studied with respect to survival and patterns of failure.

Results The median follow-up time was 4.8 years. Five-year failure-free survival for all patients according to FIGO stage I, II, and III were 87.4%, 89.0%, and 62.4 %, respectively. In multivariable analysis for relapse, positive LVSI had a hazard ratio of 4.9 (P = 0.000), which increased to 8.8 (P = 0.004) in the presence of positive nodes. For overall survival, only LVSI was significant, with a hazard ratio of 3.02 (P = 0.003). In particular, in the presence of LVSI and nodes, histological type, grade, and myometrial invasion were not significant prognosticators for relapse or overall survival.

Conclusions This model enables the separation of good prognosis patients even among poorly differentiated endometrioid, serous, and clear cell carcinoma patients and can be used in simplifying the staging of endometrial cancer and for selecting patients for high-risk endometrial cancer studies.