A Simplified Risk Stratification Method for Women With Stage I Endometrial Carcinoma

Available risk stratification methods for women with endometrial carcinoma are controversially defined. We sought to develop a simplified and an individualized prognostic index for cancer recurrence in women with International Federation of Gynecology and Obstetrics (FIGO) stage I endometrial carcinoma, solely of endometrioid histology.

We identified 976 women who underwent a hysterectomy and did not receive any adjuvant therapy. Cox proportional hazards model was used to identify independent predictors of recurrence. Prognostic groups were created based on the number of independent predictors of recurrence (0, 1, or 2 or 3 risk factors). These groups were then validated using a separate cohort of 611 women treated at another academic institution. The model's performance for predicting cancer recurrence was measured by the concordance probability estimate along with a 95% confidence interval.

Median follow-up was 65 months. The final recurrence model included 3 risk groups based on 3 independent predictors of recurrence (tumor grade 2 or 3, the presence of lymphovascular space invasion and stage IB). Five-year recurrence rates were 4%, 16%, and 44% for groups 0, 1, and 2 or 3, respectively. The performance of the model was very good with a concordance probability estimate of 0.72 and 0.80 for the development and validation cohorts, respectively.

On the basis of 3 well-known prognostic factors, we have developed and externally validated a simplified prognostic model that accurately predicts cancer recurrence in women with stage I endometrial carcinoma. This simplified predictive tool may be helpful in estimating individualized risk of recurrence and guide counseling with regard to adjuvant treatment.