What is the oesophagus?

The oesophagus (often known as the gullet) is a muscular tube situated behind the trachea (windpipe) in the throat. Food and drink pass from the back of the throat into the stomach through the oesophagus. When food is consumed the muscles at the top of the oesophagus contract, forcing food and fluid downwards into the stomach. At the lower end of the oesophagus there is a muscular valve (the sphincter), which prevents food and fluid being pushed upwards from the stomach.

Around 20% to 30% of the population appear to have a weakness of the lower oesophageal sphincter (valve), which allows acidic stomach contents to splash back up into the oesophagus, causing heartburn and regurgitation (reflux), which is the subject of a separate Core leaflet.

Cancer of the oesophagus

Cancer of the oesophagus develops from the lining of the gullet, and has the effect of narrowing the oesophagus and causing difficulty in swallowing. At first solid food tends to lodge or stick in the oesophagus, and this is followed by difficulty in swallowing liquids.

The cancerous cells may spread outside the gullet to involve nearby structures, such as lymph nodes and blood vessels in the chest, and may also be carried in the blood stream to form secondary tumours (metastases), in the liver or elsewhere.

Most cancers in the upper two-thirds of the oesophagus are known as squamous carcinomas, because they develop from the squamous (skin-like) cells which line the oesophagus.

Cancers occurring in the area where the oesophagus joins the stomach are usually adenocarcinomas, derived from stomach-like cells. Adenocarcinoma often develops when the squamous cells at the lower end of the gullet have been replaced by stomach-type (columnar) cells, which have the potential to become malignant. This condition is known as Barrett’s Oesophagus and is mentioned later in this leaflet.

What causes cancer of the oesophagus?

This cancer is particularly common in some parts of Africa and China, and is likely to be partly caused by the local diet or the way that food is preserved and cooked. In Western societies, important risk factors for cancer of the oesophagus include smoking cigarettes and drinking alcohol, particularly spirits.

A combination of smoking and spirit-drinking considerably increases the risk. It also appears that the amount of acid reflux (see above) and the period of time over which the oesophagus has been exposed to this acid, are risk factors which may explain the recent increase in the number of cases of adenocarcinoma of the oesophagus. A rare disorder of the muscles of the gullet, known as achalasia, in which there is a failure of relaxation of the muscular valve at the bottom of the gullet, very occasionally leads to cancer.