Early circulating tumour DNA kinetics measured by ultra-deep next-generation sequencing during radical radiotherapy for non-small cell lung cancer: a feasibility study

Abstract

Background: The evaluation of circulating tumour DNA (ctDNA) from clinical blood samples, liquid biopsy, offers several diagnostic advantages compared with traditional tissue biopsy, such as shorter processing time, reduced patient risk and the opportunity to assess tumour heterogeneity. The historically poor sensitivity of ctDNA testing, has restricted its integration into routine clinical practice for non-metastatic disease. The early kinetics of ctDNA during radical radiotherapy for localised NSCLC have not been described with ultra-deep next generation sequencing previously. Materials and methods: Patients with CT/PET-staged locally advanced, NSCLC prospectively consented to undergo serial venepuncture during the first week of radical radiotherapy alone. All patients received 55Gy in 20 fractions. Plasma samples were processed using the commercially available Roche AVENIO Expanded kit (Roche Sequencing Solutions, Pleasanton, CA, US) which targets 77 genes. Results: Tumour-specific mutations were found in all patients (1 in 3 patients; 2 in 1 patient, and 3 in 1 patient). The variant allele frequency of these mutations ranged from 0.05-3.35%. In 2 patients there was a transient increase in ctDNA levels at the 72 h timepoint compared to baseline. In all patients there was a non-significant decrease in ctDNA levels at the 7-day timepoint in comparison to baseline (p = 0.4627). Conclusion: This study demonstrates the feasibility of applying ctDNA-optimised NGS protocols through specified time-points in a small homogenous cohort of patients with localised lung cancer treated with radiotherapy. Studies are required to assess ctDNA kinetics as a predictive biomarker in radiotherapy. Priming tumours for liquid biopsy using radiation warrants further exploration.

Longitudinal tracking of 97 esophageal adenocarcinomas using liquid biopsy sampling

“…Here we describe the results from a commercially available pancancer mutation panel evaluated with respect to both tumor and white cell cfDNA in a large, prospectively collected and annotated sample cohort from resected EAC. [11][12][13][14][15][16]…”

The Combination of Radiotherapy With Immunotherapy and Potential Predictive Biomarkers for Treatment of Non-Small Cell Lung Cancer Patients

“…The predictive value of ctDNA in radiotherapy is still unclear yet. It has been confirmed to increase shortly after radiation and then decrease at one week in advanced NSCLC ( 136 , 137 ). They hypothesize that the ctDNA may originate from apoptotic tumor cells since higher ctDNA level was detected at 24h post radiation, which is similar to the kinetics of tumor cell apoptosis ( 136 ).…”

Targeted Liquid Biopsy Using Irradiation to Facilitate the Release of Cell-Free DNA from a Spatially Aimed Tumor Tissue

“…5 ). Previously, early spike in ctDNA has been regarded to reflect cell death and treatment efficacy [ 18 , 19 ]. In terms of tumor detection and diagnosis, the current study might be helpful for patients with small tumors, in whom ctDNA might not otherwise be detected [ 3 ].…”