Abstract: The present invention is directed to a method for diagnosing cancer, the method comprising: (a) comparing a concentration of one or more metabolite(s) present in a sample obtained from a subject with the concentration of the same one or more metabolite(s) in a reference standard, wherein the one or more metabolite(s) are selected from: a lipoprotein, myo-inositol, glucose, ?-hydroxybutyrate, ?-hydroxybutyric acid, an N-acetylated glycoprotein (NAC), threonine, lactate, lactic acid, acetate, and acetic acid; and (b) diagnosing cancer when: (i) the concentration of one or more metabolite(s) selected from: myo-inositol glucose, ?-hydroxybutyrate, ?-hydroxybutyric acid, NAC, and threonine is higher in the sample relative to the reference standard, wherein the reference standard is a non-cancer reference standard; and/or (ii) the concentration of one or more metabolite(s) selected from: a lipoprotein, lactate, lactic acid, acetate, and acetic acid is lower in the sample relative to the reference standard, wherein