The relationship between serum CA-125 level and recurrence in surgical stage I endometrial cancer patients.

Background: The majority of patients diagnosed with early stage endometrial cancer have a favorable prognosis; however, approximately 10% to 15% experience a recurrence. Therefore, the aim of the present study was to evaluate whether postoperative carbohydrate antigen 125 (CA-125) levels could be used to predict recurrence and recurrence-free survival (RFS) in patients with surgical stage I endometrial cancer.

Methods: We enrolled a total of 518 patients with stage I endometrial cancer who underwent surgical treatment between January 2010 and March 2019. Serum CA-125 levels were measured prior to surgery, as well as 6 to 12 months after surgery. Subsequently, the correlations between the CA-125 levels, cancer recurrence, and RFS were analyzed.

Results: Although the preoperative CA-125 level was not associated with the risk of cancer recurrence, the postoperative CA-125 level was found to be the only independent predictor of recurrence in both univariate and multivariate analyses. Additionally, we found that a postoperative CA-125 cutoff value of 13.75 U/mL yielded the best sensitivity and specificity for predicting cancer recurrence. Patients with a postoperative CA-125 level ≥13.75 U/mL, and those with a level <13.75 U/mL, had a median time to recurrence and a 5-year RFS rate of 35.5 vs 50.5 months and 84.7 vs 94.4%, respectively. Additionally, postoperative CA-125 levels were not found to be correlated with preoperative levels.

Conclusion: In patients with stage I endometrial cancer, a postoperative CA-125 level ≥13.75 U/mL was found to be significantly correlated with a higher recurrence rate, as well as a shorter RFS. Therefore, obtaining a follow-up CA-125 level within 6 to 12 months after staging surgery may be a promising noninvasive biomarker for predicting recurrence.