Aspirin trial launched to block heartburn's switch to cancer
At least ten per cent of the UK population will endure heartburn over the festive season. For some long-term sufferers this heartburn is a symptom of a pre-cancerous condition that is responsible for around half of all oesophageal cancers.
The Cancer Research UK funded trial will aim to prevent a precancerous condition of the oesophagus developing and its subsequent switch to cancer. Five thousand men who are at risk of the cancer will be recruited for the trial from 100 UK centres.
The number of cases of this type of oesophageal cancer has climbed quickly in recent years throughout the western world. There are over 7,000 cases and a similar number of deaths every year in the UK. The number of cases has climbed by 12 per cent over the last decade.
One of the main predisposing factors causing this cancer is a condition called Barrett's oesophagus. It is caused when stomach acid regularly ebbs back from the stomach into the oesophagus - one of the symptoms of this being heartburn. The acid damage causes a change to the cells in the lining of the oesophagus. These cells are not cancerous, but they can become so later. Barrett's oesophagus affects up to 2 per cent of the UK population.
The trial's lead researcher, Professor Janusz Jankowski, based at the Digestive Diseases Centre, University of Leicester, says: "Only a small proportion of those with Barrett's oesophagus will develop oesophageal cancer. However in the UK the number of those developing this cancer because of Barrett's oesophagus is very high compared to the rest of the western world - 3-4 times the level seen in Europe or the US.
"By successfully treating Barrett's oesophagus we could prevent up to a half of cases of oesophageal cancer in this trial."
The researchers will use aspirin and a drug that prevents acid formation in the stomach called esomeprazole to try and prevent Barrett's oesophagus.
Previous studies have suggested that aspirin reduces the number of cases of oesophageal cancer. People with Barrett's oesophagus are also more likely to suffer from heart problems - another area where aspirin has been shown to be of benefit.
However one of aspirin's side effects is an increased risk of stomach ulcers. It is hoped that esomeprazole will minimise that risk.
Esomeprazole is used as an anti-ulcer drug because it neutralizes stomach acid. A high dose of the drug may minimise damage to the lining of the oesophagus and help promote healing - blocking the subsequent switch to cancer.
Professor Jankowski adds: "The UK is at the epicentre of an explosion in this cancer. We hope these drugs will offer a simple method of preventing this particularly aggressive form of the disease.
"But the first crucial stage is to start recruiting people with Barrett's oesophagus to this important trial. These people will not only get the best possible care, they will also help uncover key clues in the fight against cancer."
Professor Robert Souhami, Director of Clinical and External Affairs at Cancer Research UK, says: "It's vital that we continue to test new prevention strategies like this. This large-scale trial may be the first step towards a promising and realistic method of preventing many cases of this form of cancer - an opportunity to close the stable door before the horse has bolted."
Notes to Editor
There are a number of symptoms of oesophageal cancer. Many of these can be caused by conditions other than oesophageal cancer, but it is important that you report them to your doctor. They can include:
- Difficulty swallowing
- Weight loss
- Pain or discomfort in the throat or back, behind the breastbone or between the shoulder blades
- Acid indigestion
- Hoarseness or chronic cough
- Vomiting or regurgitation of blood
The trial's full name is 'ASPECT: Aspirin Esomeprazole Chemoprevention Trial'. Further details can be found through CancerHelp UK.
Heartburn or gastro-oesophageal reflux disease (GORD) affects 30% of the population each month in Western countries. In a third of these individuals the damage to the oesophagus caused by the backing up of stomach acid causes erosive oesophagitis. It is those with erosive oesophagitis that have a 10% chance of developing Barrett's oesophagus (1% of population). The UK may have one the highest number of cases of Barrett's oesophagus with between 0.5 and 2 per cent of adults suffering from the condition, however, the true prevalence of this condition in the population is not known. In any case the resulting level of oesophageal cancer in some parts of the UK is 3-4 times higher than in Europe or North America.
Barrett's oesophagus - the cells lining the oesophagus start to change to look more like the cells lining the stomach. It may develop following long-term acid reflux from the stomach. The stomach acid comes back up into the oesophagus and irritates the lining. 30% of the population will have regular heartburn each month but only 1% of the population will have Barrett's oesophagus. People with Barrett's oesophagus are 50 times more likely to develop cancer of the oesophagus than the average person.
Remember - the overall risk to any individual of getting oesophageal cancer is quite small. The risk with Barrett's oesophagus may be 50 times higher, but that is still a small risk. Probably no more than 1 out of every 100 people with Barrett's oesophagus will go on to get oesophageal cancer each year. Since Barrett's oesophagus is diagnosed late in life usually after 60 years of age, the lifetime cancer risk for affected men is no more than 5-10% and less for women.
Less than 10 per cent of those diagnosed with oesophageal cancer survive for more than 5 years and the 1 year survival is less than 50%.
Esomeprazole is a 'proton pump inhibitor'. It works by blocking the production of stomach acid. These drugs are used to heal stomach and duodenal ulcers. Astra Zeneca manufactures the drug.
Aspirin will also act to prevent heart attacks in this population as well as prevent oesophageal cancer.
The trial will last 10 years - finishing in 2014 and is one of the largest cancer prevention trials in the world.