Estrogen Receptor- And Progesterone Receptor-Positive Thresholds in Predicting the Recurrence of Early Low-Risk Endometrial Cancer

BACKGROUND: Estrogen receptors (ER) and progesterone receptors (PR) have important prognostic value in endometrial cancer, but there is no recognized positive immunohistochemical threshold for predicting the recurrence of early low-risk endometrial cancer. The purpose of this study was to clarify the optimal positive thresholds of the immunohistochemical parameters the ER and PR in early low-risk endometrial cancer. METHODS: A total of 332 patients with stage IA endometrial cancer were enrolled from the First Affiliated Hospital of Chongqing Medical University and People’s Hospital of Sha ping ba District in Chongqing between January 2013 and December 2018. First, univariate and multivariate Cox regression analyses were used to analyze the correlation between various clinical factors and the prognosis of early low-risk endometrial cancer. Then, the receiver operating characteristic curve (ROC curve) and Youden index were used to determine the positive thresholds of ER and PR. RESULTS: The positive thresholds of ER and PR for predicting the recurrence of early low-risk endometrial cancer were 12% and 8%, respectively. Multivariate analysis showed that ER (P = 0.004), PR (P = 0.026), and p53 (P = 0.021) were risk factors for the prognosis of patients with early low-risk endometrial cancer. The recurrence-free survival and the overall survival in the low ER group and PR group were much lower than those in the high ER group and PR group (P < 0.001 of all). CONCLUSIONS: ER and PR positive thresholds of 12% and 8%, respectively, are the most suitable for predicting the recurrence of early low-risk endometrial cancer.