Correlation between Serum CA-125 Levels and FIGO Stage of Epithelial Ovarian Cancer

Abstract

Background: Epithelial ovarian cancer is one of the most common types of gynecological cancer that is often diagnosed at late stages due to its nonspecific clinical features and the lack of a reliable screening test. The serum cancer antigen 125 (CA-125) is widely accepted as a marker for the assessment of ovarian cancer but its correlation is different for each patient.

Objective: To determine the correlation between pretreatment serum CA-125 levels and FIGO stage among patients with epithelial ovarian cancer.

Materials and Methods: This hospital-based analytical cross-sectional study was designed to include 140 patients with histopathologically confirmed epithelial ovarian cancer from January 2022 to January 2023. The demographic characteristics, histopathological findings, pretreatment serum CA-125 levels, and FIGO stages were assessed. The Kruskal–Wallis test was used to compare the levels of CA-125 between FIGO stages, which are presented in U/mL. Spearman's rank correlation was employed to study the correlation between the CA-125 levels and the stage of the disease. A p value of < 0.05 was deemed significant.

Results: In the 140 patients, the mean age was 52.39 ± 10.74 years. High-grade serous carcinoma was the predominant histological subtype (57.9%), and 62.1% of patients had advanced-stage disease. Median CA-125 concentrations increased progressively from 64.00 U/mL in stage I to 164.80 U/mL in stage II, 449.40 U/mL in stage III, and 768.65 U/mL in stage IV. Differences across stages were statistically significant (p<0.001), with a strong positive correlation between CA-125 and FIGO stage (rho=0.755, p<0.001).

Conclusion: The analysis demonstrated a positive association between pretreatment serum CA-125 concentrations and advancing FIGO stage. CA-125 may provide supplementary information regarding disease extent but cannot independently determine ovarian cancer stage.

Keywords: CA-125; epithelial ovarian cancer; FIGO stage; tumor marker; gynecological oncology; disease progression.