Objective: Defining the reliability of cancer antigen-125-related kinetics criteria versus Gynecologic Cancer Inter Group criteria in predicting the tumor outcome after chemotherapy in patients with recurrent ovarian cancer.
Methods: A retrospective monoinstitutional assessment of CA125-related versus Gynecologic Cancer Inter Group-related parameters was performed after cytotoxic chemotherapy in patients with metastatic ovarian cancer treated from 2006 to 2011. A correlation analysis between the response and progression measurements has been performed, and the outcome has been reported.
Results: Among 42 eligible patients, tumor response and progression calculated by CA125 kinetics, with tumor response at 8 weeks and specific growth rate at progression, exhibited a significant correlation with progression-free and overall survival, similar to tumor response and progression by Gynecologic Cancer Inter Group criteria.
Conclusions: The tumor response at 8 weeks higher than 1.77 appears to be a good surrogate of clinical response, whereas the definition of progression when CA125 increases above a value double than the nadir suggests a similar performance of growth rate at progression versus Gynecologic Cancer Inter Group criteria and warrants further investigation.
Keywords: Ovarian cancer; chemotherapy; surrogate end point; tumor growth rate.