Preoperative serum CA125 level and age at diagnosis: An effective prognosis prediction tool for patients with early-stage endometrial cancer

Abstract Objective To investigate the combined predictive value of the preoperative serum cancer antigen 125 (CA125) level and age at diagnosis among patients with early-stage endometrial cancer(EC) after initial treatment. Methods We retrospectively analyzed data from patients with early-stage EC from January 1999 to December 2015 in multiple institutions in China. All patients received primary hysterectomy± bilateral salpingo-oopho rectomy and adjuvant radiotherapy for pathology-confirmed stage I and II EC(FIGO 2009 staging). In total, 447 patients with complete data on preoperative serum CA125 levels were included. All patients were divided into low-risk, intermediate-risk, high-intermediate-risk and high-risk groups according to the ESMO-ESGO-ESTRO risk classification. Binary logistic regression was used to calculate the predictive probability of 5-year overall survival (OS) for each patient, and the receiver operating characteristic (ROC) curve was used to calculate the sensitivity and specificity of variables, as well as the combined predictive value of CA125 and age. Results The median follow-up time was 59 months (3-201 months). The 5-year OS and disease-free survival (DFS) rates were 94.4% and 89.1%, respectively. Multivariate analysis showed that the preoperative CA125 level and age at diagnosis were independent prognostic factors for 5-year OS. The best cutoff value forage at diagnosis was 61 years. The cutoff values of CA125 for patients aged ≤61 years and > 61 years were 37.7 U/mL and 39.35 U/mL, respectively. Patients aged >61years with CA125 > 39.35 U/ml and patients aged ≤61years with CA125 > 37.7 U/ml were classified as theCA125-positive group; the remaining patients constituted the CA125-negative group. The area under the curve (AUC) for CA125 combined with age at diagnosis was 0.692, and the corresponding sensitivity and specificity were 68.2% and 68.2% (P<0.002), respectively, which were significantly better than the corresponding values for CA125 or age alone. Conclusions Although preoperative CA125 had limited sensitivity in predicting the prognosis for early-stage EC after initial treatment, it remains a useful serum marker for risk assessment of early-stage EC. Combining CA125 with age may increase its predictive sensitivity.