Postoperative decline in <scp>CA</scp> ‐125 as a prognostic biomarker in ovarian cancer: A systematic review and meta‐analysis

Abstract Background Cancer antigen 125 (CA‐125) is widely used for monitoring epithelial ovarian cancer, but the prognostic significance of an early postoperative decline remains uncertain. Objective This systematic review and meta‐analysis evaluated whether postoperative CA‐125 decline is associated with improved survival outcomes. Search Strategy A systematic literature search was conducted to identify studies reporting survival outcomes according to postoperative CA‐125 change following primary cytoreductive surgery. Selection Criteria We included studies investigating the prognostic impact of perioperative or postoperative CA‐125 decline and dynamics in surgically treated patients with ovarian cancer, and correlated CA‐125 changes with survival outcomes. Data Collection and Analysis A total of 12 studies met eligibility criteria for the systematic review. Main Results The primary outcomes were progression‐free survival (PFS) and overall survival (OS). Hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted and pooled using fixed‐ and random‐effects meta‐analysis models. Statistical heterogeneity was assessed using the I 2 statistic and chi‐square test. Of these, three retrospective cohort studies reported sufficient data for quantitative synthesis and were included in the meta‐analysis. Across included studies, postoperative CA‐125 decline was consistently associated with improved survival outcomes. Pooled estimates demonstrated a significant association between postoperative CA‐125 response and prognosis, with moderate heterogeneity observed between studies (I 2 approximately 60%). Conclusions Postoperative CA‐125 decline may represent a clinically significant prognostic marker associated with improved survival outcomes in ovarian cancer patients and may contribute to postoperative risk stratification. Nevertheless, the small number of studies available for quantitative synthesis, together with the considerable methodological heterogeneity among cohorts, warrants cautious interpretation of the findings and underscores the need for larger prospective studies using standardized definitions of CA‐125 response.