External validation of nomograms designed to predict lymphatic dissemination in patients with early-stage endometrioid endometrial cancer: a multicenter study

OBJECTIVE: The objective of the study was to externally validate and assess the robustness of 2 nomograms designed to predict the probability of lymphatic dissemination (LD) for patients with early-stage endometrioid endometrial cancer. STUDY DESIGN: Using a prospective multicenter database, we assessed the discrimination, calibration, and clinical utility of 2 nomograms in patients with surgically treated early-stage endometrioid endometrial cancer. RESULTS: Among the 322 eligible patients identified, the overall LD rate was 9.9% (32 of 322). Predictive accuracy according to discrimination was 0.65 (95% confidence interval, 0.61-0.69) for the full nomogram and 0.71 (95% confidence interval, 0.68-0.74) for the alternative nomogram. The correspondence between observed recurrence rate and the nomogram predictions suggests a moderate calibration of the nomograms in the validation cohort. CONCLUSION: The nomograms were externally validated and shown to be partly generalizable to a new and independent patient population. Although these tools provide a more individualized estimation of LD, additional parameters are needed to allow higher accuracy for counseling patients in clinical practice.