Pleural Glucose, CYFRA 21-1, and Radiographic Effusion Size as Predictors of Recurrent Malignant Pleural Effusion

Abstract

Background: Recurrent malignant pleural effusion (MPE) remains a significant clinical problem that often necessitates repeated interventions and impairs quality of life. Early identification of patients at high risk of recurrence is essential to optimize management strategies. This study evaluated the predictive value of pleural glucose levels, pleural CYFRA 21-1, and radiographic effusion size in patients with malignant pleural effusion.

Methods: An observational analytic study with clinical and radiologic follow-up was conducted in 60 patients with malignant pleural effusion. Patients were classified into recurrent and non-recurrent groups based on reaccumulation of pleural fluid requiring repeat thoracentesis. Pleural glucose and CYFRA 21-1 levels were measured using enzyme-linked immunosorbent assay. Radiographic effusion size was assessed on chest radiography according to the hilar level. Statistical analyses included Chi-square test, Mann–Whitney U test, and receiver operating characteristic (ROC) curve analysis.

Results: Recurrent pleural effusion occurred in 55% of patients. Effusion extending above the hilar level was observed in all recurrent cases and was significantly associated with recurrence (p < 0.001). Patients with recurrent pleural effusion had significantly lower pleural glucose levels (39.53 vs 107.46 mg/dL, p < 0.001) and higher pleural CYFRA 21-1 levels (58.61 vs 27.26 ng/mL, p < 0.001) compared with the non-recurrent group. ROC analysis demonstrated excellent predictive performance for pleural glucose (AUC 0.905) and pleural CYFRA 21-1 (AUC 0.933), with optimal cut-off values of <85.85 mg/dL and ≥44.02 ng/mL, respectively. Chest pain was the only clinical symptom significantly associated with recurrent pleural effusion (p < 0.001).

Conclusion: Lower pleural glucose levels, elevated pleural CYFRA 21-1 levels, and radiographic effusion extending above the hilum are significantly associated with recurrent malignant pleural effusion. These parameters may assist in risk stratification and individualized management of patients with MPE.