Correlation between CA-125 serum level and response by RECIST in a phase III recurrent ovarian cancer study

Gynecol Oncol. 2011 Aug;122(2):350-5. doi: 10.1016/j.ygyno.2011.04.005. Epub 2011 May 5.


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.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • CA-125 Antigen / blood*
  • Disease-Free Survival
  • Female
  • Humans
  • Middle Aged
  • Neoplasm Recurrence, Local / blood*
  • Neoplasm Recurrence, Local / mortality
  • Ovarian Neoplasms / blood*
  • Ovarian Neoplasms / mortality


  • CA-125 Antigen