Introduction: There is no guideline-recommended screening test for esophageal cancer, a cancer that occurs in approximately 1 in 125 men and 1 in 417 women in the US. Risk factors for esophageal adenocarcinoma include gastroesophageal reflux disease, Barrett’s esophagus, obesity, and smoking. A multi-cancer early detection (MCED) test that analyzes methylation patterns of cell-free DNA in the blood using sequencing assays and machine-learning classifiers is available as a complement to existing single-cancer screening tests. The MCED test reports either (1) ‘cancer signal detected’ with 1 or 2 cancer signal origin (CSO) prediction(s) or (2) ‘cancer signal not detected’. A case of esophageal adenocarcinoma is presented here to demonstrate early detection using the MCED test and to review the diagnostic journey following a cancer signal detected (positive) test result. Case Description/Methods: An asymptomatic 63-year-old White male (BMI: 27 kg/m2) with history of peptic ulcer disease was screened using the MCED test. He reported moderate alcohol use (6/week) and no tobacco use. His last colonoscopy was 5 years prior to using the test. Nine days after a blood sample was collected for analysis by the MCED test, a positive test result (CSO prediction=Stomach/Esophagus) was reported and communicated to the patient (Day 1). Computed tomography (CT) of the chest, abdomen, and pelvis with contrast showed no significant findings (Day 13). A submucosal bulge just below the gastroesophageal junction (GEJ) was noted on upper endoscopy. The lesion, and area above the GEJ were extensively biopsied (Day 15). Pathologic evaluation confirmed diagnosis of Clinical Stage I esophageal adenocarcinoma with superficial focally invasive adenocarcinoma arising in a background of intestinal metaplasia with high grade dysplasia (Day 29). The patient underwent total gastrectomy without complications (Day 104). He will undergo appropriate follow-up 6 months post-op. Discussion: The MCED test detected a cancer signal and predicted a gastrointestinal CSO for an asymptomatic individual with Clinical Stage I esophageal cancer. Diagnostic resolution was achieved within 1 month and treatment was provided with curative intent. Given that there is no guideline-recommended screening test available for esophageal cancer, the use of this MCED test detected cancer early, directed diagnostic workup, and potentially improved outcomes for this asymptomatic patient.

Citation Format: David DeAtkine Jr. A case of stage I esophageal adenocarcinoma diagnosed using a multi-cancer early detection test. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P059.