What is oesophageal cancer?
Oesophageal cancer begins from abnormal cells in the innermost layer (mucosa) of the oesophagus. A tumour can start at any point along the length of the oesophagus.
If it is not found and treated early, oesophageal cancer can spread through the lymphatic system to nearby lymph nodes or through the bloodstream to other parts of the body, most commonly the liver. It can also grow through the oesophageal wall and invade the windpipe and lungs.
Learn more about:
- The oesophagus and digestive system
- Types of oesophageal cancer
- What are the risk factors?
- Who gets oesophageal cancer?
The oesophagus and digestive system
The oesophagus and stomach are part of the upper gastrointestinal (GI) tract, which is part of the digestive system. The digestive system helps the body break down food and turn it into energy.
The oesophagus (food pipe or gullet) is a long, muscular tube that delivers food, fluids and saliva from the mouth and throat to the stomach. A valve (sphincter) at the end of the oesophagus stops acid and food moving from the stomach back into the oesophagus.
The stomach is a hollow, muscular organ in the upper left part of the abdomen, located between the end of the oesophagus and the beginning of the small bowel (small intestine). The stomach expands to store food that has been swallowed. It also helps with the absorption of some vitamins and minerals.
In the stomach, acidic (gastric) juices are released from glands in the stomach lining (mucosa). These juices break down food into a thick fluid, which then moves into the small bowel. In the small bowel, nutrients from the broken-down food are absorbed into the bloodstream. The waste matter moves into the large bowel (large intestine), where fluids are reabsorbed back into the body. The solid waste matter is passed out of the body as a bowel movement.
The stomach and the oesophagus
The different layers of tissue (known as the wall) in the oesophagus include:
- Mucosa (moist innermost layer) – made up of squamous cells
- Submucosa (supports the mucosa)
- glands in the submucosa produce fluid (mucus)
- this fluid helps to move food through the oesophagus
- Muscle layer
- known as the muscularis propria
- produces contractions to help push food down the oesophagus and into the stomach
- Outer layer
- known as the adventitia
- connective tissue supporting the oesophagus
Types of oesophageal cancer
Oesophageal cancer can occur in different types of cells that exist in the oesophagus.
The two main subtypes are:
- Oesophageal squamous cell carcinoma – starts in the thin, flat cells in the lining of the oesophagus, which are called squamous cells. It often begins in the middle and upper part of the oesophagus. In Australia, squamous cell carcinomas are less common than adenocarcinomas.
- Oesophageal adenocarcinoma – Barrett’s oesophagus occurs when the squamous cells lining the lower section of the oesophagus change into glandular cells. A tumour that starts in glandular cells is called an adenocarcinoma. Adenocarcinomas are now the most common form of oesophageal cancer in Australia.
Less common types of cancer
Other less common types of cancer can affect the stomach and oesophagus. These include small cell carcinomas, lymphomas, neuroendocrine tumours, and gastrointestinal stromal tumours.
These types of cancer aren’t discussed here and treatment may be different. Call Cancer Council 13 11 20 for information about these types of cancer, or speak to someone in your medical team.
What are the risk factors?
The exact causes of oesophageal cancer are unknown, but the factors listed below may increase your risk. However, having one or more of these risk factors does not mean you will develop cancer.
Some known risk factors for oesophageal squamous cell carcinoma include:
- alcohol consumption
- older age (being over 60)
- infection with human papilloma virus (HPV)
Some known risk factors for oesophageal adenocarcinoma include:
- being overweight or obese
- medical conditions, including gastrooesophageal reflux disease (GORD) and Barrett’s oesophagus
- older age (being over 60)
- a personal or family history of gastro-oesophageal disorders, such as hernia, polyps, ulceration or oesophagitis
GORD and Barrett’s oesophagus
Gastro-oesophageal reflux disease (GORD) and Barrett’s oesophagus are risk factors for oesophageal adenocarcinoma. Reflux is when stomach acid backs up into the oesophagus.
Over time, stomach acid can damage the walls of the oesophagus, causing inflammation or ulceration (oesophagitis). In some people, this may cause the squamous cells lining the oesophagus to be replaced by glandular cells. This condition, called Barrett’s oesophagus, can lead to oesophageal adenocarcinoma. Most people with Barrett’s oesophagus will not develop oesophageal cancer.
Who gets oesophageal cancer?
This is an uncommon cancer. In Australia, about 1400 people are diagnosed with oesophageal cancer each year. Men are nearly three times more likely than women to be diagnosed with this cancer.
It is more common in people over 60, but can occur at any age. About one in 158 men and one in 575 women are likely to develop oesophageal cancer before the age of 75.