Malignant pleural effusion risk based on a novel tool using homocysteine and carcinoembryonic antigen in pleural fluid: A multicenter study

•MPER model demonstrated high diagnostic accuracy (AUC: 0.891) for MPE.•Novel use of pleural fluid homocysteine and cea significantly improved MPE diagnosis.•MPER achieved 84.3 % sensitivity and 80.7 % specificity at a cut-off > 35.3 %.•Multicenter study validated the model’s applicability across different hospitals. This multicenter study aimed to evaluate the Malignant Pleural Effusion Risk (MPER) diagnostic accuracy in distinguishing between benign and malign pleural effusion. Methods: MPER is based on pleural fluid Homocysteine (HCY) and carcinoembryonic antigen (CEA) that were measured using three different methods. MPER was calculated by assessing a previously published probabilistic model: Probability (%) = 100× (1 + e-z)-1, where Z = 0.5471 × [HCY] + 0.3846 × [CEA]–8.2671. A total of 301 patients were included (140 MPE). MPER demonstrated a high AUC (0.891), sensitivity (84.3 %), and specificity (80.7 %) with a cut-off > 35.3 %. The MPER model demonstrated a high diagnostic accuracy supporting its use as a novel and powerful tool.