Cross-sectional analysis of circulating tumor DNA in primary colorectal cancer at surgery and during post-surgery follow-up by liquid biopsy
Open Access
- 20 April 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Journal of Experimental & Clinical Cancer Research
- Vol. 39 (1), 1-12
- https://doi.org/10.1186/s13046-020-01569-z
Abstract
Liquid biopsy (LB) in early-stage, non-metastatic colorectal cancer (CRC) must be sensitive enough to detect extremely low circulating tumor DNA (ctDNA) levels. This challenge has been seldom and non-systematically investigated. Next generation sequencing (NGS) and digital PCR (dPCR) were combined to test tumor DNAs (tDNAs) and paired ctDNAs collected at surgery from 39 patients, 12 of whom were also monitored during the immediate post-surgery follow up. Patients treated for metastatic disease (n = 14) were included as controls. NGS and dPCR concordantly (100% agreement) called at least one single nucleotide variant (SNV) in 34 tDNAs, estimated differences in allelic frequencies being negligible (±1.4%). However, despite dPCR testing, SNVs were only detectable in 15/34 (44.1%) ctDNAs from patients at surgery, as opposed to 14/14 (100%) metastatic patients. This was likely due to striking differences (average 10 times, up to 500) in ctDNA levels between groups. NGS revealed blood-only SNVs, suggesting spatial heterogeneity since pre-surgery disease stages, and raising the combined NGS/dPCR sensitivity to 58.8%. ctDNA levels at surgery correlated with neither tumor size, stage, grade, or nodal status, nor with variant abundance in paired tDNA. LB sensitivity reached 63.6% when ctDNA was combined with CEA. Finally, persistence and absence of ctDNA on the first conventional (month 3) post-surgery follow-up were associated with fast relapse and a disease-free status in 3 and 7 patients, respectively. A simple clinical NGS/dPCR/CEA combination effectively addresses the LB challenge in a fraction of non-metastatic CRC patients.Keywords
Funding Information
- Associazione Italiana per la Ricerca sul Cancro (19503)
- Associazione Italiana per la Ricerca sul Cancro (19052)
- H2020 Future and Emerging Technologies (633937)
This publication has 34 references indexed in Scilit:
- Towards Precision Medicine in the Clinic: From Biomarker Discovery to Novel TherapeuticsTrends in Pharmacological Sciences, 2016
- Development and Clinical Validation of a Blood Test Based on 29-Gene Expression for Early Detection of Colorectal CancerClinical Cancer Research, 2016
- Limits and potential of targeted sequencing analysis of liquid biopsy in patients with lung and colon carcinomaOncotarget, 2016
- Droplet digital PCR of circulating tumor cells from colorectal cancer patients can predict KRAS mutations before surgeryMolecular Oncology, 2016
- Mutation tracking in circulating tumor DNA predicts relapse in early breast cancerScience Translational Medicine, 2015
- Analysis of circulating tumour DNA to monitor disease burden following colorectal cancer surgeryGut, 2015
- Comparative sequencing analysis reveals high genomic concordance between matched primary and metastatic colorectal cancer lesionsGenome Biology, 2014
- Detection of Circulating Tumor DNA in Early- and Late-Stage Human MalignanciesScience Translational Medicine, 2014
- Analysis of Circulating Tumor DNA to Monitor Metastatic Breast CancerThe New England Journal of Medicine, 2013
- Interpreting Diagnostic Test Accuracy StudiesSeminars in Hematology, 2008