Results of Liquid Biopsy Studies by Next Generation Sequencing in Patients with Advanced Stage Non-small Cell Lung Cancer: Single Center Experience from Turkey

Several studies demonstrated the utility of plasma-based cell-free circulating tumor DNA (ccfDNA) in determination of mutations in non-small cell lung cancer (NSCLC). We aimed to report our results of next generation sequencing (NGS) using liquid biopsy in patients with NSCLC. Patients with advanced stage NSCLC were enrolled and their genomic profiling results were recorded. Next generation sequencing targeted panel includes 19 hot-spot genes. The plasma was separated from the peripheral blood sample and ccfDNAs were isolated for NGS. We performed genomic profiling in 100 patients (20 females and 80 males) with a median age of 59.3 (range 26-79). A second liquid biopsy was performed in eight patients who developed progressive disease after the first treatment. The study population had adenocarcinoma (AC) (n = 73), squamous cell carcinoma (SCC) (n = 14), or NSCLC-NOS (not otherwise specified) (n = 13). In the SCC group, three of 14 patients had variants on EGFR and MET genes. In the AC and NSCLC-NOS groups, 39 out of 86 patients (45.3%) had variants. The most common one was in the EGFR gene (n = 27, 31.4%) including seven mutations related to drug resistance and two were polymorphisms. Three patients had both driver and resistance mutations (EGFR T790M, n = 2; KRAS exon 2 G12S and MET exon 14 E1012K, n = 1). Fifteen patients (17.4%) had an activating EGFR mutation and eight patients (9.3%) had variants in the KRAS gene. We reported our results regarding genomic profiling related to treatment using liquid biopsy in patients with NSCLC. Advantages of this method are the non invasiveness and reproducibility.