Invitae, University College London (UCL), and the Francis Crick Institute announced new data from their TRACERx lung cancer research collaboration funded by Cancer Research UK and sponsored by UCL. The data, presented by Professor Charles Swanton of UCL and the Francis Crick Institute at the International Society of Liquid Biopsy (ISLB) Congress, further validate the value of liquid biopsy as a less invasive and more comprehensive approach to guiding personalized cancer treatment in the absence of detectable disease by clinical imaging. Previously reported findings from the TRACERx cohort found that monitoring for cancer circulating tumor DNA (ctDNA) based minimal residual disease (MRD) detected relapse of non-small cell lung cancer (NSCLC) up to three years earlier than standard of care imaging surveillance in some instances. The study used a new blood-based informatic tool called ECLIPSE (Extraction of CLonality from LIquid bioPSiEs) with an earlier iteration of the Invitae Personalized Cancer Monitoring (PCM?) liquid biopsy assay to analyze plasma samples of patients in the TRACERx study. With this approach, data demonstrated multiplex-anchored PCR sequencing of the plasma samples enhanced MRD lead times relative to standard of care surveillance scanning and allowed holistic sampling of clonal dynamics, or tumor heterogeneity, with prognostic implications for disease progression. Invitae's PCM is a pan-cancer, tumor-informed liquid biopsy assay that uses next-generation sequencing powered by Anchored Multiplex PCR (AMP?) to monitor MRD with high sensitivity at low variant allele fractions. The service employs a combination of a tumor profile, blood tests and personalized assays based on a patient's tumor with the goal of earlier detection of cancer recurrence through ctDNA before it is detectable by imaging or other conventional methods. ECLIPSE, developed by the Cancer Research UK TRACERx team at UCL and the Francis Crick Institute, uses a standardized algorithm that helps resolve tumor tissue-based sample bias. Coupling Invitae's PCM assay with ECLIPSE, the researchers analyzed 972 longitudinal plasma samples from 136 TNM I-III NSCLC patients in TRACERx who had undergone multiregion whole exome sequencing of primary tumor and relapse tissue and had 364 surveillance scans. Seventy-five of these patients experienced a recurrence of their surgically resected disease. The researchers concluded that multiplex-anchored PCR with trinucleotide specific background models improves NSCLC relapse detection compared to standard of care clinical follow up. Using ECLIPSE, plasma samples of less than 1% purity can be used to accurately profile the clonal structure of tumors at diagnosis, during treatment and at relapse, which impacts patient outcome and has the potential to guide personalized medicine.