A genetic modification in the mucous membrane of the esophagus, the Barrett esophagus, can lead to esophageal cancer. If certain biomarkers are contained in these tissue alterations, so-called miDNA, these are extremely short DNA strands, it could be an indication that this preliminary stage of esophageal cancer indeed leads to cancer.
http://www.news-medical.net/news/20151228/Genetic-modification-in-esophagus-can-lead-to-esophageal-cancer.aspx
Genetic modification in esophagus can lead to esophageal cancer