Liquid Biopsy Analysis as a Tool for TKI-Based Treatment in Non-Small Cell Lung Cancer

Abstract

The treatment of non-small cell lung cancer (NSCLC) has recently evolved with the introduction of targeted therapy based on the use of tyrosine kinase inhibitors (TKIs) in patients with certain gene alterations, including EGFR, ALK, ROS1, BRAF, and MET genes. Molecular targeted therapy based on TKIs has improved clinical outcomes in a large number of NSCLC patients with advanced disease, enabling significantly longer progression-free survival (PFS). Liquid biopsy is an increasingly popular diagnostic tool for treating TKI-based NSCLC. The studies presented in this article show that detection and analysis based on liquid biopsy elements such as circulating tumor cells (CTCs), cell-free DNA (cfDNA), exosomes, and/or tumor-educated platelets (TEPs) can contribute to the appropriate selection and monitoring of targeted therapy in NSCLC patients as complementary to invasive tissue biopsy. The detection of these elements, combined with their molecular analysis (using, e.g., digital PCR (dPCR), next generation sequencing (NGS), shallow whole genome sequencing (sWGS)), enables the detection of mutations, which are required for the TKI treatment. Despite such promising results obtained by many research teams, it is still necessary to carry out prospective studies on a larger group of patients in order to validate these methods before their application in clinical practice.

Detection and Molecular Characterization of Circulating Tumour Cells: Challenges for the Clinical Setting

“…A multiparameter liquid biopsy analysis in plasma cfDNA and paired CTCs in NSCLC patients under osimertinib treatment was performed at different time points at the DNA-mutation, DNA-methylation and gene expression levels. Molecular methodologies used to detect molecular targets associated with TKI treatment should be further validated in large prospective studies [ 89 ]. Based on this, recently, Crystal digital PCR (STILLA, France) was used to detect and quantify %MAFs of EGFR mutations in ctDNA and paired CTCs.…”

Mutational and copy number analysis of numerous sorted circulating and disseminated tumour cells to interrogate subclonal evolution in advanced breast cancer.

“…Although mutation detection in DNA extracted from CTC-enriched samples demonstrated activating mutations in e.g. EGFR, KRAS, and AR genes in patients suffering from lung, colorectal, or castration-resistant prostate cancer respectively (17,18,19), sequencing of enriched fractions is complicated by low levels of tumour-specific templates and contamination by abundant leukocyte-derived sequences, limiting the sensitivity and specificity (20,21). Molecular analysis of pure isolated CTCs enables the detection of multiple mutations within the same cell, in order to decipher tumour heterogeneity and map clonal evolution (22,23,24).…”

“…The enumeration of CTCs bears prognostic significance in patients with MBC (10,11) and other malignancies (12,13). Furthermore, phenotypical and molecular characterization of CTCs are informative with regards to targetable aberrations present during the course of the disease (14,15,16,17).…”

Miniaturized Laser Probe for Exosome-Based Cancer Liquid Biopsy

“…Liquid biopsy, as a rising approach for cancer diagnosis, has gained extensive awareness in recent years due to the unique advantages of noninvasiveness, ease of performance, less risks of causing metastasis, and real-time insights into tumor status. , Exosomes, a subclass of phospholipid-bilayered extracellular vesicles with a size of 50–150 nm released from cells by exocytosis, play a vital role in intercellular communication and cancer progression. Exosomes are present in all body fluids, carrying substantial information from originating cells and thus are highly specific for organotropic characteristics, especially useful for diagnosis and prognosis.…”