Pleural fluid markers for malignant pleural effusions

A method of diagnosing a malignant disease or survival term thereof, comprising

• obtaining samples of effusions from a subject in need of diagnosis,
• measuring the normalized intensity of a biomarker selected from the group consisting of acetone, 3-hydroxybutyrate, 1-methylhistamine, 1-methylnicotinamide, 2-methylglutarate, 2-oxoglutarate, 3-OH-3-methylglutarate, 3-methyladipate, 4-aminohippurate, acetone, adenine, alanine, creatine, dimethylamine, formate, fumarate, glucose, glycolate, imidazole, lactate, methylamine, O-acetylcarnitine, oxalacetate, phenylacetylglycine, phenylalanine, tryptophan, tyrosine, cis-aconitate, myo-inositol, trans-aconitate, leucine, valine, acetate, acetoacetate, creatinine, and trimethylalanine-N-oxide in the effusions, and
• comparing the normalized intensity of the biomarker in the effusions of the subject in need of diagnosis and the normalized intensity in a normal or non-diseased subject,
• wherein the subject is diagnosed with a malignant disease when the normalized intensity of the biomarker in the effusion of the subject in need of diagnosis is at least 1.5 fold greater than the normalized intensity of the biomarker in the effusion of the normal or non-diseased subject.