The oesophagus (gullet) is the muscular tube that carries food from the mouth to the stomach (see diagram below). In Barrett's oesophagus, there are changes in the cells on the inner lining of the oesophagus at the lower end.
Barrett’s oesophagus can occur at any age. It can affect both men and women, but it is more common in men.
The cell changes in Barrett’s oesophagus can sometimes develop into something called dysplasia. Dysplasia can be either low-grade or high-grade. In low-grade dysplasia, the cells are slightly abnormal. In high-grade, the cells are more abnormal.
Barrett's oesophagus is not a cancer. However, over time the cells can become more abnormal. Sometimes this develops into a cancer called adenocarcinoma of the oesophagus. Cancer develops when the normal workings of a cell go wrong and the cell becomes abnormal. The abnormal cell keeps dividing, making more and more abnormal cells. These eventually form a lump (tumour).
Less than 2 out of every 200 people (less than 1%) in the UK have Barrett's oesophagus. And very few people with this condition develop cancer. About 3 in every 100 people (3%) who have Barrett's oesophagus will develop oesophageal cancer during their lifetime.