Preoperative and pre-chemotherapy CA-125 levels in high-risk early-stage ovarian cancer – An NRG/GOG study

Objectives: To determine clinical significance of preoperative and pre-chemotherapy CA-125 in high-risk early-stage epithelial ovarian cancer patients. Methods: All patients with stage IA/IB and grade 3, stage IC, clear cell, or completed resected stage II cancer were enrolled in a phase III trial and treated with chemotherapy. Kaplan-Meier method and Cox proportional hazards model were used for statistical analyses. Results: 427 patients with high-risk early-stage ovarian cancer were enrolled. Of 213 patients with preoperative CA-125 data, 79% had elevated CA-125. Median preoperative CA-125 level was 103 U/mL. Patients with ≤10, 11–15, and > 15 cm tumors had median preoperative CA-125 levels of 62, 131 and 158 U/mL, respectively (p = 0.002). For the 350 patients with data for pre-chemotherapy CA-125 level, 69% had elevated pre-chemotherapy CA-125 above 35 U/mL with median value of 65 U/mL. However, age, race, stage, cell type and grade of disease were not correlated with CA-125 levels before and after surgery. On multivariate analysis, elevated pre-chemotherapy CA-125 independently predicted worse recurrence-free survival (HR = 2.13, 95% CI: 1.23–3.69; p = 0.007) and overall survival (HR = 1.99, 95% CI: 1.10–3.59; p = 0.022) after adjusting for age, stage, cell type and grade of disease. Compared to those with normal CA-125, patients with elevated pre-chemotherapy CA-125 had lower recurrence-free survival (RFS, 87% vs. 75%; p = 0.007) and overall survival (OS, 88% vs. 82%; p = 0.02). However, preoperative CA-125 was not prognostic of RFS (p = 0.699) or OS (p = 0.701). Conclusions: Preoperative CA-125 was elevated in nearly 80% of high-risk early-stage ovarian cancer patients. Pre-chemotherapy CA-125 was associated with recurrence-free and overall survival; however, preoperative CA-125 was not prognostic.