Preoperative Inflammatory Markers as Predictors of Ovarian Tumor Malignancy: A Retrospective Diagnostic Study

Background and Objectives: Ovarian cancer remains the most lethal gynecologic malignancy, largely due to late diagnosis and the limitations of currently available diagnostic tools. Systemic inflammatory markers derived from routine blood tests have emerged as potential low-cost biomarkers, reflecting the interaction between tumor biology and the host immune response. This study aimed to evaluate the association and diagnostic value of preoperative inflammatory markers in distinguishing malignant from non-malignant ovarian tumors. Materials and Methods: This retrospective, single-center observational study included 780 adult female patients diagnosed with ovarian tumors and treated surgically between January 2020 and December 2025. Preoperative hematological parameters were obtained from complete blood count analyses performed before any therapeutic intervention. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were calculated. Comparisons were performed among benign, borderline, and malignant tumors. To avoid collinearity between mathematically interrelated inflammatory indices, three separate multivariable logistic regression models were constructed, each including age, CA-125, and one inflammatory index. Diagnostic performance of the individual inflammatory indices was assessed using receiver operating characteristic (ROC) curve analysis. Results: Patients with malignant tumors were significantly older and exhibited higher NLR and PLR values and lower LMR values than patients with non-malignant tumors (all p < 0.001). In separate multivariable models adjusted for age and CA-125, higher NLR (OR = 1.79, 95% CI: 1.41–2.27, p < 0.001) and PLR (OR = 1.43, 95% CI: 1.17–1.75, p = 0.001) remained significantly associated with malignant ovarian tumors, whereas higher LMR was inversely associated with malignancy (OR = 0.66, 95% CI: 0.52–0.85, p = 0.001). ROC analysis demonstrated moderate discriminative ability for NLR and PLR (AUC = 0.72 for both), whereas LMR showed lower discriminative performance (AUC = 0.64). Conclusions: Preoperative systemic inflammatory indices are significantly associated with ovarian tumor malignancy. NLR and PLR were positively associated with malignant disease, whereas LMR showed an inverse association, and these relationships remained significant after adjustment for age and CA-125. However, their individual discriminative performance was modest, suggesting that these readily available inflammatory indices should be considered complementary rather than standalone biomarkers for preoperative risk assessment.