Diagnostic Power of the Fibrinogen-to-Albumin Ratio for Estimating Malignancy in Patients with Adnexal Masses: A Methodological Study.

Background: Adnexal masses are common in women across different age and hormonal states: pregnancy, premenopause, and postmenopause. Ovarian carcinoma, a malignancy arising in the adnexa, poses significant health risks. While malignancy risk increases with age and postmenopausal status, current methods for stratifying borderline cases remain inadequate, potentially leading to over- or undertreatment that may affect fertility or survival. Methods: This retrospective study was conducted with 318 adult women who were diagnosed with adnexal masses and underwent surgery at a university hospital between 2020 and November 2023. Patient data were retrieved from the hospital's electronic medical record system. Routinely measured preoperative serologic parameters-carbohydrate antigen (CA)125, CA19-9, CA15-3, carcinoembryonic antigen (CEA), Alpha-fetoprotein (AFP), Lactate dehydrogenase (LDH), and fibrinogen-to-albumin ratio (FAR) levels-were analyzed alongside final histopathological results. No procedures outside routine clinical practice were performed. Diagnostic performance of each marker was evaluated using receiver operating curve (ROC) analysis. Results: A total of 318 patients with adnexal masses were analyzed. The FAR levels were significantly elevated in malignant compared to borderline and benign groups (p < 0.001), and FAR alone showed 47% sensitivity and 91% specificity for borderline tumors, whereas CA125 showed 70% sensitivity and 85% specificity. Multivariate models combining FAR, CA125, and CA15-3 achieved the highest diagnostic accuracy, with superior AUCs compared to single biomarkers. Conclusions: FAR is a simple, accessible inflammatory marker that complements CA125 by enhancing specificity. Combination of multiple markers with the highest sensitivity and specificity, together with FAR, may reduce the risk of both false negatives, offering a more balanced and accurate diagnostic tool for preoperative stratification of borderline tumor cases.