Probing gender-specific lipid metabolites and diagnostic biomarkers for lung cancer using Fourier transform ion cyclotron resonance mass spectrometry

Background: There are no effective clinical biomarkers for early and specific detection of lung cancer (LC). The changes in the levels of some serum metabolites of LC patients are associated with patient gender and LC stages. Methods: Serum metabolites of the LC patients (n = 58) and healthy controls (n = 495) were performed using direct-infusion positive ion electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry in combination with univariate and partial least squares discriminant analyses (PLS-DA). Results: Univariate analysis indicated that 141 of the 212 serum metabolites were significantly changed in the LC patients compared with healthy controls. PLS-DA model, based on the 141 metabolites, demonstrated the differential metabolite distribution in single-sex LC patients compared with the corresponding healthy controls, and also in LC females compared with LC males. Several lipids comprising fatty acid derivations, sphingomyelin (SM) and lysophosphatidylcholine (LPC) were associated with the LC progression. Classification using oleamide, long chain acyl carnitines, LPC(18:1), LPC(20:4), LPC(20:3), LPC(22:6), and SM(16:0/1) as a biomarker panel resulted in remarkable separation between the LC patients and healthy controls with sensitivity and specificity of 100% and 91%, respectively. Conclusion: The serum metabolites found in this study may play essential roles in gender-specific LC detection and early diagnosis of cancer. (C) 2012 Elsevier B.V. All rights reserved.