title: Diagnostic utility of CYFRA 21-1 in malignant pleural effusion.
abstract: OBJECTIVE
  The diagnostic utility of the tumour marker CYFRA 21-1 in malignant pleural effusion is not yet clear. This study was designed to evaluate the diagnostic utility of serum and pleural fluid CYFRA 21-1 in malignant pleural effusion.
  
  
  METHODS
  The validity of serum and pleural fluid CYFRA 21-1 was determined in 62 patients with exudative pleural effusion (27 malignant and 35 benign). The diagnosis of malignant pleural effusion was defined by cytological or histological results.
  
  
  RESULTS
  A statistically significant difference between the geometric means of CYFRA 21-1 levels in pleural fluid of benign and malignant aetiologies was observed (11.2 vs 63.3 ng/mL, P < 0.0001). In addition, there was a significant difference in the serum levels (0.95 vs 5.55 ng/mL, P < 0.0001). The sensitivity and specificity of pleural fluid CYFRA 21-1 in malignant pleural effusion, at the cut-off value of 55 ng/mL, was 74.1% and 97.1%, respectively. The sensitivity and specificity of serum CYFRA 21-1, at the cut-off value of 2.5 ng/mL, was 81.5% and 97.1%, respectively. Using a combination of serum and pleural fluid CYFRA 21-1 level, the sensitivity increased to 88.9%.
  
  
  CONCLUSIONS
  Serum and pleural fluid CYFRA 21-1 are useful as measures in differentiating malignant from benign pleural effusion.
authors.affiliation: Division of Respiratory Disease and Tuberculosis, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. siwds@mahidol.ac.th
authors.forename: W
authors.initials: W
authors.lastname: Dejsomritrutai
authors.forename: S
authors.initials: S
authors.lastname: Senawong
authors.forename: B
authors.initials: B
authors.lastname: Promkiamon
mesh_terms: D000951:Antigens, Neoplasm / Q000097:blood; D005122:Exudates and Transudates / Q000737:chemistry; D005260:Female; D006801:Humans; D053539:Keratin-19; D007633:Keratins; D008297:Male; D016066:Pleural Effusion, Malignant / Q000175:diagnosis* / Q000209:etiology; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D000951:Antigens, Neoplasm; D053539:Keratin-19; C102012:antigen CYFRA21.1; D007633:Keratins