Abstract
BackgroundIn standard pre-analytical conditions, an isolation step is required for circulating tumor DNA (ctDNA) analysis. The need for this step remains unclear with the development of ultrasensitive detection technologies such as digital PCR (dPCR). The aim of our study was to evaluate the ctDNA detection by dPCR platform either directly from plasma (plasma group, PG) or after an isolation step (isolation group, IG). MethodsWe included 17 patients corresponding to a selection of 43 blood samples in metastatic colorectal cancer patients. For each sample, ctDNA was analyzed with or without isolation step (IG and PG, respectively) using KRAS, NRAS and BRAF mutations identified from the tumor tissue. ctDNA detection was performed after a preamplication step using dPCR platform (QuantStudio™ 3D Digital PCR System). ctDNA detection rate and mutant allelic frequencies (MAF) were compared between IG and PG. ResultsOur results showed a detection rate at 93% in IG vs. 88% in PG. The concordance rate between the two groups was 91% (39/43) for ctDNA detection with the four discordant cases occurring in patients with low MAF (<0.5%). The mean value of MAF were 16.9±18.9 and 18.5±18.9 for IG and PG, respectively (p=0.24). The correlation coefficient r2 for MAF was 0.82 between the two methods (p<0.0001). ConclusionIn conclusion, our results show that direct detection of ctDNA from unpurified plasma is a feasible approach, particularly from sample with high MAF (>0.5%).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.