Value of serum CA125 levels in patients with high-risk, early stage epithelial ovarian cancer

Abstract

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 ≤ 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.