ABSTRACT Oral Americans diagnosis, early like used clinical, There defined features, performance methylation retrospective methylation Epigenetic personalized with construct patients squamous cell carcinoma (OSCC) is on the rise, increasing by two-thirds in 20 years. Each year 30,000 are diagnosed with OSCC, and 50% of these cases are early stage I/II. Despite the early stage at these patients suffer from significant morbidity, and a 5-year mortality rate of 40%. Treatment for stage OSCC is highly variable, ranging from just cancer resection, to the addition of adjuvant treatments elective neck dissection (END), radiotherapy (RT), or chemoradiation (chemoRT). While stage is primarily to assess risk and assign adjuvant treatment, its prognostic value is low. There is currently no reliable histologic or molecular marker to determine individual risk in patients within the same cancer stage. is a need to develop a r obust prognostic biomarker to guide treatment and improve survival. We recently a mortality risk score for early stage OSCC patients, composed of methylation and clinicopathologic using a discovery cohort and The Cancer Genome Atlas (TCGA) data, which has strong predictive to identify patients at high risk of death in 5 years. In this application, we propose to validate this biomarker in early stage OSCC patients with known 5-year survival from a multi-institutional cohort of formalin-fixed, paraffin embedded (FFPE) tissues. We will combine our validated (molecular) biomarker with clinicopathologic (non-molecular) markers to construct the high-Risk And clinicopathologic Score for Oral caNcer ( REASON ) score. We hypothesize that this score wil accurately predict the risk of 5-year cancer-specific mortality . The study will proceed three aims. Firstly, we will perform an epigenome wide association study ( EWAS) using the EPIC array, to and validate the REASON score with a retrospective cohort (cohort 1, n=400) of early stage OSCC with known 5-year survival outcome, who underwent cancer resection only. Secondly, l we will apply the REASON score to a separate retrospective cohort (cohort 2, n=400) of early stage OSCC patients who underwent adjuvant treatments (i.e., END, RT, chemoRT) in addition to cancer resection. We will determine whether these adjuvant treatments confer a survival advantage in high risk (high REASON score) patients over cancer resection alone. We will also determine whether these adjuvant treatments could be spared in low risk (low REASON score) patients. in certifiable collect signatures prognostic assembles clinically We will also perform technical validation of the methylation features discovered the EWAS with MethylCap-Seq (MC-Seq), a robust, Clinical Laboratory Improvement Amendments (CLIA) platform. Lastly, in an exploratory aim, we will prospectively enroll early stage OSCC patients and noninvasive brush swabs and cancer tissues. We will determine the concordance of methylation between paired brush swabs and can...