Objectives: To evaluate in a large phase III recurrent ovarian cancer trial (OVA-301): 1) the concordance between CA-125 level vs. best overall response (OR) and progression-free survival (PFS) determined by radiological assessment 2) the impact of early CA-125 changes over the subsequent radiological response, and 3) the prognostic value of CA-125 response and CA-125 PFS to predict radiological response and PFS.
Methods: Assessment of response in the entire randomized population was performed by the Response Evaluation Criteria in Solid Tumors 1.0 (RECIST) and modified Rustin criteria for CA-125 determination.
Results: Most CA-125 decreases were observed in RECIST responders (82% of patients treated with the combination and 74% in the PLD alone). CA-125 progression preceded RECIST progression in 35% of patients with a median lead time of 8.4 weeks. A high concordance rate between CA-125 PFS status at 4 months (PFS4) and CA-125 response as a predictor of PFS4 (87%) and radiological response (79%) was found in the combination, with high positive predictive value for radiological PFS4 (92%) and high negative predictive value for OR (90%). An early CA-125 decrease was predictive for the ultimate response since it was found in a high rate of RECIST responders.
Conclusion: Radiological response was preceded by a favorable predictive CA-125 decrease in a high proportion of patients, suggesting that CA-125 evaluation may be an appropriate tool for tumor assessment in patients with ovarian cancer.
Copyright © 2011 Elsevier Inc. All rights reserved.