title: Combined CA125 and mesothelin levels for the diagnosis of malignant mesothelioma.
abstract: BACKGROUND
  Malignant mesothelioma is an aggressive, uniformly fatal tumor. Serum markers would be useful for the diagnosis of this disease. One potential marker is mesothelin. The purpose of this study was to study the mesothelin biomarker in a large patient cohort and to determine if another biomarker, CA125, improves on the sensitivity of mesothelin in the diagnosis of mesothelioma.
  
  
  METHODS
  Serum levels of mesothelin and CA125 were determined by commercially available assays in 117 samples obtained at diagnosis from patients with pleural malignant mesothelioma, 33 healthy, asbestos-exposed individuals, 53 patients with asbestos-related lung or pleural disease, and 30 patients presenting with benign pleural effusions. Cross-validated sensitivities were determined, and receiver operator characteristic curves were generated to compare the diagnostic accuracy of the biomarkers.
  
  
  RESULTS
  CA125 had a cross-validated sensitivity of 27% for mesothelioma patients at a specificity of 95% relative to asbestos-exposed individuals, or 50% relative to individuals with benign pleural effusions. Mesothelin had a cross-validated sensitivity of 52% for mesothelioma patients, at a sensitivity of 95% relative to individuals with benign lung or pleural disease. CA125 and mesothelin levels were discordant in > 50% of mesothelioma patients. Combining the data from the two biomarkers using a logistic regression model did not improve sensitivity for detecting mesothelioma above that of the mesothelin marker alone.
  
  
  CONCLUSIONS
  Combining mesothelin and CA125 data does not improve the sensitivity of mesothelioma diagnosis over mesothelin alone. The use of both markers potentially increases the number of patients who can be monitored.
authors.affiliation: National Research Centre for Asbestos Related Diseases, 4th Floor, G Block, Sir Charles Gairdner Hospital, Verdun St, Nedlands, WA 6009, Australia. creaneyj@cyllene.uwa.edu.au
authors.forename: Jenette
authors.initials: J
authors.lastname: Creaney
authors.forename: Ivonne
authors.initials: I
authors.lastname: van Bruggen
authors.forename: Michelle
authors.initials: M
authors.lastname: Hof
authors.forename: Amanda
authors.initials: A
authors.lastname: Segal
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Musk
authors.forename: Nick
authors.initials: N
authors.lastname: de Klerk
authors.forename: Nora
authors.initials: N
authors.lastname: Horick
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Skates
authors.forename: Bruce W S
authors.initials: BW
authors.lastname: Robinson
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood* / Q000378:metabolism; D018394:CA-125 Antigen / Q000097:blood* / Q000378:metabolism; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood* / Q000378:metabolism; D000090204:Mesothelin; D008654:Mesothelioma / Q000175:diagnosis*; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
chemical_list: D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D000090204:Mesothelin