Objectives: The aim of this study was to ascertain whether serum CA125 level is predictive of disease progression in patients with high-risk, early stage (stage IA/B grade 3, stage IC any grade, stage I clear cell, or stage II) epithelial ovarian cancer who have achieved a complete response to chemotherapy.
Methods: Between January 1998 and April 2004, we reviewed the records of 95 patients with high-risk, early stage epithelial ovarian cancer who had elevated CA125 levels at the time of diagnosis and were complete responders after 6 cycles of adjuvant paclitaxel/carboplatin chemotherapy. A receiver operating characteristic curve was used to determine the most useful CA125 level in predicting disease progression and Cox proportional hazards models adjusted for covariates were used for analyses.
Results: The 5-year progression-free survival (PFS) was 70.5%. The optimal cutoff point of CA125 after completing adjuvant chemotherapy to predict disease progression was 12 U/mL (sensitivity, 71.4%; specificity, 82.1%). On multivariate analysis, CA125 level>12 U/mL after completing adjuvant chemotherapy was an independent prognostic factor predictive for disease progression. The risk of recurrence was higher for CA125 level>12 U/mL (hazards ratio=10.567; P<0.001). The 5-year PFS rate for patients with CA125 level< or =12 U/mL was 83.3%, which was higher than a PFS of 37.5% for CA125>12 U/mL (P<0.001).
Conclusions: CA125 level after 6 cycles of adjuvant chemotherapy is a strong independent prognostic factor for high-risk, early stage epithelial ovarian cancer after achieving a complete response.