Objective: To determine the relevance between the cut-off level of cancer antigen 125 (CA 125) level and long-term prognosis in high-grade serous ovarian cancer (HGSCs).
Study design: Observational study.
Place and duration of study: Departments of Oncology, Medeniyet University Goztepe Education and Research Hospital, and Kartal Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey, from January 2017 to June 2019.
Methodology: Medical records of 230 women with HGSC were reviewed randomly from two Oncology Clinics. Descriptive analysis and CA 125 marker levels were evaluated with five years of disease-free survival rate (DFS) and overall survival rate (OS). Patients were divided into groups of high and low initial CA 125 levels (cut-off ≥385U/ml). The ability of initial serum CA 125 levels in predicting the presence of marker-recurrence of ovarian cancer were analysed using ROC (Receiver operating characteristics) curve analysis.
Results: Statistically significant predictive value of initial CA 125 level was calculated as 385U/ml (p=0.008). The 5-year DFS of high and low CA 125 levels for all stages in HGSC was statistically significant (p<0.001). The sub-group analysis demonstrated that the significant survival difference was especially in FIGO stage III. Patients with HGSC <385 U/ml had a significantly improved 5-year DFS and OS rates within stage III disease: 5-year DFS (p = 0.008) and 5-year OS (p = 0.004) according to the stratification of CA 125 level.
Conclusion: Initial CA 125 level appeared to be of beneficial clinical predictive value for HGSC. Key Words: Initial CA 125, Tumor marker, High-grade serous ovarian cancer, Disease-free survival, Overall survival, Predictive value.