Platelet linoleic acid is a potential biomarker of advanced non-small cell lung cancer

New parameters that could be used as tumor markers for lung cancer would be valuable. Our aim was to analyze the fatty acid profiles of total lipids from erythrocytes and platelets from patients with advanced non-small cell lung cancer (NSCLC), chronic obstructive pulmonary disease (COPD) and asthma to reveal the fatty acids that could be used as NSCLC biomarkers. In our study, 50, 15 and 15 patients with advanced NSCLC, COPD and asthma and 50 healthy subjects were enrolled. Fatty acid profiles were investigated using gas chromatography/mass spectrometry followed by ROC (receiver operating characteristics) curves analysis to gain information about biomarkers. Sialic acid (SA) and cytokeratins were measured by the thiobarbituric acid and immunoradiometric methods respectively. Useful fatty acid markers were as follows: erythrocytes, 22:0 and linoleic acid (LA, 18:2n6); platelets, 16:0, 18:0, and LA. At the cutoff value to obtain maximum accuracy, the best biomarker was platelet LA, with higher diagnostic yields than the commonly used markers SA or cytokeratins (100%, 76%, 75% and 86% sensitivity, specificity, positive predictive value and accuracy, respectively). These findings suggest that platelet LA might be used as a biomarker of NSCLC in relation to different aspects of the disease process that now needs to be explored.