Analysis of Plasma Cell-Free DNA by Ultradeep Sequencing in Patients With Stages I to III Colorectal Cancer

Abstract

This cohort study investigates the use of longitudinal data from ultradeep sequencing of cell-free DNA in Danish patients with colorectal cancer.

Low Abundance of Circulating Tumor DNA in Localized Prostate Cancer

“…Amongst recurrent patients, ctDNA detected prior to chemotherapy also tracked with worse overall survival [36]. Similar successes were achieved in a cohort of 130 colorectal cancer patients, in which a personalized ctDNA detection assay detected ctDNA in 88.5% of preoperative plasma, and 70% of patients with detectable ctDNA at the start of adjuvant chemotherapy subsequently recurred [21].…”

“…Comprehensive cancer panels, as well as whole genome and exome sequencing, can also be used to interrogate somatic copy number alterations (SCNAs) from plasma DNA, with varying resolution depending on the sequence modality and depth [18,19]. Personalized, bespoke sequencing assays have shown sensitivity for the detection of urothelial and colorectal cancers [20,21]. The success of these approaches has been thought to depend upon high tumor burden and the propensity of the tumor to shed circulating tumor DNA (ctDNA) into the bloodstream with proportional contribution of subclones to the ctDNA pool [22,23].…”

Circulating epigenetic biomarkers for detection of recurrent colorectal cancer

“…Cancer April 1, 2020 A number of studies have personalized ctDNA biomarkers to patient-specific mutation profiles by first detecting which somatic alterations are present in the primary tumor and then applying either 1 biomarker or a panel of the biomarkers for measurement in blood. 6,7 This technique, however, has limitations because the heterogeneity of tumor tissue and the development of subclones, which may further change during therapy, can result in a blood ctDNA mutation profile different than what was found in the primary tumor with the original testing. 8 Aberrantly methylated genes are common to CRC, 9 and these methylation changes can also be detected in ctDNA.…”

Radiomics Features of 18F-fluorodeoxyglucose Positron-Emission Tomography as a Novel Prognostic Signature in Colorectal Cancer

“…Prognostic biomarkers may help to select patients at high risk of recurrence, allowing customization of the follow-up monitoring process for the individual patient. The detection of circulating tumor (ct) cells or ctDNA after surgery may provide good sensitivity and specificity, although such a test would have to be compared with CEA-based detection of tumor recurrence [36][37][38][39]. Patients with a high risk of recurrence may be good candidates for liquid biopsy-based follow-up; this would be a more reasonable approach in the context of medical resource use, considering the additional cost imposed by liquid biopsies.…”