Prognostic value of CA125 kinetics, half-life, and nadir in the treatment of epithelial ovarian cancer: a systematic review and meta-analysis

Objective To investigate the prognostic value of cancer antigen 125 (CA125) related variables on progression free survival and overall survival in primary and recurrent ovarian cancers. Method A comprehensive review of the Medline, Embase, and Cochrane Library databases was conducted to identify relevant literature on survival outcomes according to the ELIMination Rate Constant K (KELIM), Gynecologic Cancer InterGroup (GCIG) CA125 response criteria, CA125 half-life, and CA125 nadir levels during first line or later line chemotherapy. The search included articles published before February 2023. Cut-off values determining the favorable/unfavorable score of each study were extracted, and pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were analyzed using a random effects model to identify the relationship between survival outcomes of the favorable/unfavorable groups, which was determined by an individual model using CA125 kinetics. Results A total of 27 studies with 14 444 patients with epithelial ovarian cancer were included in this meta-analysis. In primary ovarian cancer, a favorable KELIM score, determined by individual modeled cut-off values, was associated with a significant progression free survival (HR 0.53, 95% CI 0.45 to 0.62) and overall survival (HR 0.51, 95% CI 0.43 to 0.62) benefit in the primary setting. The favorable KELIM scored group also correlated with a better progression free survival (HR 0.54, 95% CI 0.47 to 0.62) in relapsed disease. We failed to demonstrate a better prognostic value of the GCIG response criteria and the CA125 half-life for progression free survival and overall survival. Conclusion Novel chemotherapy response scores, such as KELIM, may be more clinically relevant than other prognostic models using CA125 kinetics, being directly associated with a more favorable survival in both the primary and relapsed setting in patients with epithelial ovarian cancer. Study registration The systemic review and meta-analysis were registered in PROSPERO (CRD42023385512).