Why is the ctDNA Colorectal Cancer Panel (HD842) offered at very low allele frequencies?

MRD (minimal or measurable residual disease) detection is critical to predict disease outcome and to select the intensity of further treatment strategies in solid tumors like colorectal cancer. The primary method of identifying MRD is to detect circulating tumor DNA (ctDNA) released from residual tumor cells as they die. Because the residual tumor cells are very low in number post-treatment, MRD can only be detected through highly sensitive methods, such as droplet digital PCR (ddPCR) with a limit of detection (LOD) of 0.1% allelic frequency (AF), or Next Generation Sequencing (NGS). Therefore, our ctDNA Colorectal Cancer Panel is offered at a 1.25% AF.