Associations Between Non-Genetic Risk Factors and DNA Methylation Alterations in Barrett's Esophagus and Its Progression to Esophageal Adenocarcinoma.

Esophageal cancer (EC) is one of the most aggressive cancers of the digestive system, with two main subtypes: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Over four decades, the frequencies of EAC and Barrett's esophagus (BE), the known precursor lesion for EAC, have sharply increased in North America and Europe. This is mainly due to lifestyle and risk factors such as gastroesophageal reflux disease (GERD), obesity, and smoking. BE development to EAC involves numerous molecular modifications, including genetic and epigenetic alterations. Epigenetic changes, such as aberrant DNA methylation, play a critical role in the pathogenesis and progression of BE. This review discusses how non-genetic risk factors contribute to DNA methylation changes driving the transformation from BE to EAC, providing insights into the potential of developing methylation-based biomarkers for early diagnosis, risk stratification, and therapeutic intervention.