A TRACERx pilot analysis presented at AACR described how a tumor-informed whole-genome ctDNA sequencing approach using Ultima Genomics’ duplex sequencing method can detect intermediate-risk relapse groups without bespoke assays. The work leveraged ppmSeq (paired plus-minus sequencing) to call variants with error suppression. In a pilot cohort of 45 participants, the ctDNA results from blood samples taken 120 days post-surgery showed strong concordance with prior TRACERx data and predicted relapse-free survival over roughly eight years after surgery. The approach also enabled tracking of a median of ~15,000 mutations per patient, compared with ~1,800 mutations per patient using custom tumor-informed capture panels. Researchers said the method could improve risk stratification and help identify new cancer-related signatures. Following the pilot, they plan to apply ppmSeq to a larger cohort of around 400 individuals and explore additional tumor-agnostic signature detection. For MRD and risk stratification, the key operational appeal is avoiding custom assay design while maintaining high-fidelity variant calling.