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).