Assessment of diagnostic efficacy: High fluorescent cells combined with CEA, NSE, and Cyfra21-1 in Malignant Pleural...

To determine routine and biochemical parameters, as well as tumor markers, that are significantly different between malignant pleural effusion (MPE) and benign pleural effusion (BPE), and to evaluate the diagnostic efficacy of the combination of routine and biochemical parameters, along with carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and cytokeratin 19 fragment (Cyfra21-1) measurements in pleural effusion for identifying MPE.

1,238 patients with pleural effusion from the First Affiliated Hospital of Xi'an Jiaotong University were recruited and categorized into two groups: MPE (n = 397) and BPE (n = 841). Biomarker levels were compared, and receiver operating characteristic (ROC) curves were performed on the statistically significant indicators to assess the diagnostic efficacy for MPE.

High-Fluorescent cells (HFC), CEA, NSE, and Cyfra21-1 were significantly elevated in MPE (P < 0.001) and positively correlated with its presence (P < 0.001). The area under the curve (AUC), cutoff value, sensitivity, and specificity were: [0.726 (95% CI: 0.696-0.756), 17.5, 8.5%, 57.4%]; [0.894 (95% CI: 0.873-0.914), 5.78, 80.7%, 88.6%]; [0.703(95% CI: 0.672-0.735), 10.97, 59.3%, 71.9%] and [0.774 (95% CI: 0.746-0.802), 34.61, 74.7%, 67.9%], respectively. When focusing on multi-biomarker strategy, the combination of HFC and CEA offered the highest diagnostic efficiency (AUC: 0.868; 95% CI: 0.847-0.889), with a sensitivity of 88.4% and a specificity of 70.7%.

HFC, CEA, NSE, and Cyfra21-1 are valuable diagnostic markers for MPE, with optimal cutoff values of 17.5 × 10⁶/L, 5.78 ng/mL, 10.97 ng/mL, and 34.61 ng/mL, respectively. The HFC+CEA combinations enhanced diagnostic sensitivity and clinical utility.