Abstract 2427: The development of a tissue-agnostic genome-wide methylome enrichment MRD assay for applications across the cancer care continuum for head and neck malignancies

Abstract Background: Plasma-based tests to quantify circulating cell-free DNA cancer signal have emerged as viable applications across the cancer continuum, from early detection to optimal disease management. Here we demonstrate the feasibility of a tissue-agnostic, genome-wide methylome enrichment platform based on cell-free methylated DNA immunoprecipitation and high throughput sequencing (cfMEDIP-seq) for cancer detection, cancer signal quantification, and prognostication in head and neck cancer (HNC). Methods: Pre-treatment plasma samples from individuals with newly diagnosed stage I-IV HPV+ or HPV- HNC were analyzed with a bisulfite-free, non-degradative, genome-wide methylome enrichment platform using 5-10 ng of cell-free DNA. For cancer detection, a machine learning classifier used differentially methylated regions to distinguish cancers from non-cancer controls. The area under the receiver operating characteristic curve (AUC) and 95% confidence intervals were calculated. Cancer signals were quantified from average normalized counts across informative methylated regions and a 95% specificity threshold. For prognostication, events were defined as recurrence, progression, or death due to HNC, whichever occurred earliest. Time to event was compared for samples with cancer signal quantities above versus below the threshold. Post-treatment and longitudinal plasma samples from individuals with Stage I-IVB HNC (HPV+ and HPV- included) will be analyzed for recurrence prediction and detection of relapse. More than 100 patients and 300 samples will be analyzed. Results: For cancer detection, 92 pre-treatment plasma samples from HNC cases were distinguished from 674 controls with an AUC of 0.96 (0.94, 0.98). The AUC was 0.93 (0.86, 1.0) for Stage I, 0.93 (0.83, 1.0) for Stage II, 0.96 (0.94, 0.99) for Stage III, and 0.97 (0.96, 0.99) for Stage IV. For prognostication, 91 pre-treatment samples were included (7 stage I, 16 stage II, 23 stage III, 45 stage IV). Median follow-up time was 50.6 months with 27 events. Likelihood of recurrence or progression was significantly higher in samples with cancer signal above the threshold [hazard ratio 5.4 (95% CI 2.25, 12.95), log-rank P<0.001]. In the upcoming analysis, data will be reported on the ability to predict recurrence and relapse in post-treatment samples. Conclusions: The cfMeDIP-seq approach demonstrated robust detection of HNC, across all stages and subtypes, and the ability to predict recurrence and progression from pre-treatment samples. We will report training data with cross validation to predict recurrence and relapse using post-treatment and longitudinal sampling. Collectively, data from these studies indicate that genome wide methylome enrichment has multiple use cases across the care continuum for patients with HNC. Citation Format: Geoffrey Liu, Jun Min, Yarong Wang, Justin Burgener, Ben Brown, Karen Budhraja, Junjun Zhang, Owen Hall, Shu Yi Shen, Martha Pienkowski, Shao Hui Huang, Laurie Ailles, Katrina Rey-McIntyre, Jeremy B. Provance, Eduardo Sosa, Cynthia Frye, Scott Bratman, Brian Allen, Joshua T. Jones, Abel Licon, Jing Zhang, Anne-Renee Hartman, Daniel D. De Carvalho. The development of a tissue-agnostic genome-wide methylome enrichment MRD assay for applications across the cancer care continuum for head and neck malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2427.