Lipid Perturbations in the Saliva, Plasma, and Feces of Patients with Non-Small Cell Lung Cancer

A comprehensive lipid profile was analyzed in patients with non-small cell lung cancer (NSCLC) using nanoflow ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. The study investigated 297, 202, and 166 lipids in saliva, plasma, and fecal samples, respectively, comparing NSCLC patients to healthy controls. Lipids with significant changes (>2-fold, p<0.05) were further analyzed in each sample type. Both saliva and plasma exhibited similar lipid alteration patterns in NSCLC, but saliva showed more pronounced changes and fecal lipids had weak correlation with those of saliva and plasma. Total triglycerides (TGs) increased (>2–3 folds) in plasma and saliva but decreased in fecal samples. Three specific TGs (50:2, 52:5, and 54:6) were significantly increased in NSCLC across all sample types. A common ceramide species (d18:1/24:0) decreased in both plasma and saliva but increased in fecal samples. Additionally, phosphatidylinositol 38:4 decreased by approximately 2-fold in plasma and saliva. Phosphatidylserine 36:1 was selectively detected in saliva and showed a subsequent decrease, making it a potential biomarker for predicting lung cancer. The study identifies 27 salivary, 10 plasma, and 16 fecal lipids as candidate markers for NSCLC by statistical evaluations. Moreover, it highlights the potential of saliva in understanding changes in lipid metabolism associated with NSCLC.