Multimodal analysis of methylomics and fragmentomics in plasma cell-free DNA for multi-cancer early detection and localization

The non-invasive approach for early cancer detection promises a screening assay accessible for everyone. However, the delivery of this promise is limited due mostly to the high sequencing cost associated with available assays. Here, we developed a multimodal assay called SPOT-MAS (Screening for the Presence Of Tumor by Methylation And Size) to simultaneously profile methylomics, fragmentomics, copy number, and end motifs in a single workflow using targeted and shallow genome-wide sequencing of cell-free DNA. We applied SPOT-MAS to 738 nonmetastatic patients with breast, colorectal, gastric, lung and liver cancer, and 1,550 healthy controls. SPOT-MAS detected the five cancer types with a sensitivity of 72.4% and specificity of 97.0%, with AUC of 0.95 (95% CI 0.93-0.96). For tumor-of-origin, a graph convolutional neural network was adopted and could achieve an accuracy of 0.7. In conclusion, our study demonstrates comparable performance to other early cancer detection assays while requiring significantly lower sequencing depth, making it economically feasible for population-wide screening.