Compared to traditional methods, circulating tumor DNA (ctDNA) detection provides a non-invasive and easy-to-use method for cancer diagnosis, prognosis determination, and treatment guidance. ctDNAs are a popular class of liquid biopsy biomarkers that are thought to be readily detectable in the plasma of cancer patients even in the early stages of their disease. CD BioSciences' goal is to help our clients develop reliable biomarkers for the evaluation and management of pancreatic cancer (PC) based on the breadth and depth of our expertise and advanced technology. We provide ctDNA isolation, purification, and detection to assist in the development of ctDNAs as biomarkers for PC diagnosis to meet your research project needs and to rapidly advance your project goals.
Overview of ctDNA
ctDNA represents a subset of cell-free DNA (cfDNA) that can be derived from apoptotic and necrotic tumor cells, living tumor cells, or even CTCs. ctDNA accounts for approximately 0.1% to >90% of all cfDNA, depending on a number of factors, especially the stage of cancer. Studies have shown that the percentage of ctDNA is lower in early-stage cancers than in advanced malignancies. For PC, ctDNA was detected in 48% of patients with localized tumors, but in more than 80% of patients with advanced cancer. ctDNA detection is generally based on the target mutation, such as KRAS and EGFR, and has been used to predict the recurrence of PC.
Fig. 1 Circulating tumor cells (CTCs) and ctDNA present in the blood and detectable using liquid biopsies.
The service offering at CD BioSciences
- ctDNA isolation and purification
Compared to CTC detection, the ctDNA tests provide personalized disease detection and show a higher sensitivity for early detection of cancer. The isolation and purification of ctDNA are challenging due to the short half-life of ctDNA and its easy degradation during processing. Therefore, we focused on the most important factors in the extraction of ctDNA, including the selection of specimen types, specimen collection procedures, specimen handling, and methods of isolation and purification.
- ctDNA detection
As for ctDNA detection, we employ droplet PCR (dPCR), whole-genome sequencing, and targeted sequencing. dPCR uses droplets to compartmentalize individual DNA strands and therefore has a high sensitivity, thus facilitating the detection of low allele frequency variants. While the next-generation sequencing (NGS) approaches can detect a wider range of mutations (including single nucleotide variants, structural variants, and copy number variations) with higher coverage but lower sensitivity. We focus on the following aspects to facilitate the use of ctDNAs in PC screening/early detection, including:
-Assays based on ctDNA fragment size
-Assays based on specific genetic alterations, including mutations and copy number changes
-Assays based on altered methylation patterns
ctDNA analysis may be more sensitive and accessible, not only for non-invasive molecular analysis of tumors but also for monitoring tumor dynamics during treatment. CTC analysis has its own advantages, CTC makes functional analysis such as drug testing possible. Therefore, we recommend the use of CTCs and ctDNA for parallel or complementary analysis to improve the accuracy of PC diagnosis. Contact us for details of our services.
- Han, Xiao, Junyun Wang, and Yingli Sun. "Circulating tumor DNA as biomarkers for cancer detection." Genomics, proteomics & bioinformatics 15.2 (2017): 59-72.
- Jaworski, Jedrzej J., Robert D. Morgan, and Shivan Sivakumar. "Circulating cell-free tumour DNA for early detection of pancreatic cancer." Cancers 12.12 (2020): 3704.