Abstract
Objectives. To determine the clinical and prognostic significance of CA-125 trends prior to, during, and after chemotherapy in high-risk early-stage epithelial ovarian cancer patients. Methods. All patients were enrolled in a phase III randomized trial (GOG 157) following upfront surgery for grade 3 stage IA/IB, stage IC, or stage II disease, and had been treated with either three or six cycles of carboplatin/paclitaxel. Kaplan-Meier method and Cox proportional hazards model were used to evaluate recurrence-free survival (RFS) and overall survival (OS). Results. Of 350 patients, the median pre-chemotherapy CA-125 was 65 (IQR: 31-129). 71% of Whites had an elevated CA-125 compared to 47% of non-Whites (p= 0.006). Following the first cycle of chemotherapy, 74% of those with elevated CA-125 had normalization. Those who had normalization of CA-125 after 1 cycle hadsignificantly better 5-year RFS (81% vs. 65%, p= 0.003) and OS (87% vs. 75%, p= 0.009) compared to those who did not normalize (defined as =35 U/mL). The pattern of CA-125 change following chemotherapy cycle 1, from normal to normal vs. elevated to normal vs. elevated to elevated had corresponding RFS of 87% vs. 80% vs. 68% (p= 0.013), and OS of 92% vs. 88% vs. 77% (p= 0.009). However, the percent decline (p= 0.993) and absolute nadir normal value of CA-125 (0-10 vs. 11-35 U/mL) were not predictive of outcome (p= 0.4). Conclusions. Normal baseline CA125 and normalization of this biomarker after the first cycle of chemotherapy were associated with better survival in high-risk early-stage epithelial ovarian cancer patients.