Objective: To initially determine the critical values of the immunohistochemical parameters estrogen receptor (ER) and progesterone receptor (PR) in endometrial cancer

and to better evaluate the significance of ER and PR as prognostic and predictive indicators of endometrial cancer. Methods: A total of 473 patients with stageⅠ-Ⅲendometrial cancer who underwent surgical treatment were included in this study. The receiver operating characteristic curve (ROC curve) and the Jordan index were used to determine the critical values of the immunohistochemical parameters ER and PR for predicting the recurrence of endometrial cancer. Cox regression model was used to analyze the correlation between the factors and the prognosis of endometrial cancer. Results: The optimal critical values of ER and PR for predicting recurrence of patients with stageⅠ-Ⅲendometrial cancer are 45% and 33%

respectively. Univariate analysis showed that ER (Wald=57.948

P=0.000) and PR (Wald=50.538

P=0.000) were risk factors for endometrial cancer recurrence. Multivariate analysis showed that ER (Wald=9.076

P=0.003) was an independent risk factor for endometrial cancer recurrence. Conclusion: When the critical value of ER and PR was 45% and 33% respectively

it is most suitable for predicting the recurrence of endometrial cancer.