Panel of serum metabolites discriminates cancer patients and healthy participants of lung cancer screening - A pilot study

Introduction. Blood biomarkers may support early diagnosis of lung cancer by enabling pre-selection of candidates for computed tomography screening or discrimination between benign and malignant screeningdetected nodules. We aimed to identify features of serum metabolome distinguishing individuals with earlydetected lung cancer from healthy participants of the lung cancer screening program. Methods. Blood samples were collected in the course of a low-dose computed tomography screening program performed in the Gdansk district (Northern Poland). The analysis included 31 patients with screening-detected lung cancer and the pair-matched group of 92 healthy controls. The gas chromatography coupled to mass spectrometry (GC/ MS) approach was used to identify and quantify small metabolites present in serum. Results. There were several metabolites detected in the sera whose abundances discriminated patients with lung cancer from controls. Majority of the differentiating components were downregulated in cancer samples, including amino acids, carboxylic acids and tocopherols, whereas benzaldehyde was the only compound significantly upregulated. A classifier including nine serum metabolites allowed separation of cancer and control samples with 100% sensitivity and 95% specificity. Conclusions. Signature of serum metabolites discriminating between cancer patients and healthy participants of the early lung cancer screening program was identified using a GC/MS metabolomics approach. This signature, though not validated in an independent dataset, deserves further investigation in a larger cohort study.