OA04.7. Development of a Prediction Model for Esophageal Squamous Cell Carcinoma Using Somatic Mosaicism in the Buccal Mucosa

Abstract

Esophageal Cancer: Esophageal Carcinogenesis The oral cavity, pharynx, and esophagus are covered by anatomically contiguous squamous epithelium, and alcohol consumption and smoking are well-established common cancer risk factors for the three organs. The aim of this study is to analyze somatic mosaicism in normal buccal mucosa and develop a predictive model for esophageal squamous cell carcinoma (ESCC) based on buccal mucosal remodeling. We analyzed ESCC driver mutant clones using error-corrected sequencing of buccal swabs and examined the association between driver mutations and clinical factors. A total of 707 buccal swabs of three different sizes (20, 28, and 254 mm2) from 222 subjects (121 ESCC patients and 101 controls) were analyzed, resulting in the detection of 23,537 mutations, with frequencies of NOTCH1, TP53, and CHEK2. Aging and smoking had a consistent impact on the accumulation of driver mutations regardless of germline risk. In contrast, alcohol consumption led to approximately 20-fold faster accumulation of driver mutations in individuals with germline risk compared to those without, even at the same level of alcohol intake. Logistic regression analysis was used to construct a prediction model for ESCC based on buccal mucosal remodeling, with the most accurate model achieving an AUC of 0.85 using 28 mm2 buccal swabs. In conclusion, we established a risk assessment method for ESCC using buccal mucosa, which may contribute to early detection of ESCC.