Hotspot Mutations Detectable by Next-generation Sequencing in Exhaled Breath Condensates from Patients with Lung Cancer

Background: Genetic alterations occurring in lung cancer are the basis for defining molecular subtypes and essential for targeted therapies. Exhaled breath condensate (EBC) is a form of non-invasive sample that, amongst components, contains DNA from pulmonary tissue. Next-generation sequencing (NGS) was herein used to analyze mutations in EBC from patients with lung cancer. Materials and Methods: EBC was collected from 26 patients with cancer and 20 healthy controls. Amplicon-based sequencing using Ion Ampliseq Colon and Lung Cancer gene panel v2 was applied. Results: The sequencing was successful in 17 patients and 20 controls. EBC from patients revealed 39 hotspot mutations occurring in: adenomatous polyposis coli (APC), v-raf murine sarcoma viral oncogene homolog B (BRAF), discoidin domain receptor tyrosine kinase 2 (DDR2), epidermal growth factor receptor (EGFR), erb-b2 receptor tyrosine kinase 4 (ERBB4), F-box and WD repeat domain containing 7 (FBXW7), fibroblast growth factor receptor 1 (FGFR1), FGFR3 (fibroblast growth factor receptor 3), Kirsten rat sarcoma viral oncogene homolog (KRAS), mitogen-activated protein kinase kinase 1 (MAP2K1), met proto-oncogene (MET), neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), phosphatase and tensin homolog (PTEN), ret proto-oncogene (RET), SMAD family member 4 (SMAD4), serine/threonine kinase 11 (STK11), and tumor protein p53 (TP53) genes. EBC from controls revealed 35 hotspot mutations. The average mutant allele fraction was higher in patients than controls. Conclusion: NGS can identify mutations in EBCs from patients with lung cancer. This could provide a promising non-invasive method for the assessment of gene mutations in lung cancer.