The diagnostic value of serum inflammation, coagulation and tumor indexes in differentiating stage III and IV ovarian endometriotic cysts

Background: Ovarian endometriotic cysts (OEC) are classified into early (I-II) and advanced (III-IV) stages. Stage IV OEC is characterized by severe adhesions and anatomical distortion that complicate surgical management. Accurate preoperative differentiation between stage III and IV OEC is crucial for optimizing surgical planning and patient outcomes. Objective: This study aimed to investigate the diagnostic value of serum inflammatory, coagulation, and tumor markers in differentiating stage III from stage IV OEC. Methods: = 73) OEC who underwent surgical treatment between January 2013 and December 2019. Patients were divided into training (70%) and test (30%) cohorts. Inflammatory markers, coagulation parameters, and tumor markers were evaluated. Multivariate logistic regression identified independent predictors, and a nomogram was constructed to predict stage IV disease. Results: Stage IV patients demonstrated significantly elevated platelet-to-lymphocyte ratio (PLR), thrombin time, fibrinogen (FIB) levels, and carbohydrate antigen 125 (CA125) concentrations compared to stage III patients. Multivariate analysis identified PLR, FIB, and CA125 as independent predictors of stage IV OEC. The combined nomogram (PLR, FIB, and CA125) achieved superior diagnostic performance with an AUC of 0.81 (95% CI: 0.75-0.88) in the training cohort and 0.78 (95% CI: 0.65-0.91) in the test cohort, outperforming individual biomarkers. Conclusion: The integration of PLR, FIB, and CA125 provides a practical, non-invasive, and cost-effective approach for preoperative differentiation of stage III and IV OEC, which potentially facilitates improved surgical planning and personalized patient management.