A BREATH test similar to one used to catch drink-drivers could soon be used to help two forms of cancer, according to researchers.

The medical invention is undergoing trials and experts hope it will be able to detect stomach and oesophageal cancer.

Scientists at Imperial College in London took samples of hundreds of patients’ breath to test them for acids found in the body that are often linked to the cancers.

Initially, results have been promising. They hope further trials will result in breath tests being used to detect cancers earlier.

Both stomach and oesophageal cancer, which affects the gullet, are often diagnosed later, leading to poorer survival rates than other forms of the disease that are picked up more quickly.

Cancer charity bosses have welcomed the results.

Dr Justine Alford, Cancer Research UK’s senior science information officer, said: “Oesophageal and stomach cancers are difficult to treat, so we urgently need to develop non-invasive ways that can accurately pick up the disease at an earlier stage, when treatment is more likely to be successful. Using breath tests is one such intriguing possibility and the next steps will need to establish if this technique can detect the disease at its earliest stages.

“More research is also needed to see if there are any potential harms linked to using the test, such as people being treated unnecessarily.”

The breath test could avoid doctors having to carry out uncomfortable endoscopy examinations, which require a flexible telescope to be put down the throat and into the patient’s stomach.

Dr Sheraz Markar, one of the trial researchers, said: “At present, the only way to diagnose oesophageal cancer or stomach cancer is with endoscopy. This method is expensive, invasive and has some risk of complications.

“A breath test could be used as a non-invasive, first-line test to reduce the number of unnecessary endoscopies.

“In the longer term this could also mean earlier diagnosis and treatment, and better survival.”

In Scotland the rate of oesophageal cancer has been rising steadily since 1990, official figures show.

About 660 people were diagnosed with the disease in 1990, while in 2000 it had risen to 745. Figures from 2014 show 932 people were diagnosed in Scotland.

Conversely, the rates of stomach cancer have fallen in Scotland in the same period, with more than 1,000 people diagnosed in 1990 and about 680 diagnosed in 2014.

Each year in the UK about 6,682 people are diagnosed with stomach cancer and 4,576 die from the disease. Figures for oesophageal cancer show 8,919 new cases per year and 7,790 deaths.

For the new study, breath samples were collected from 335 patients at three London hospitals. Of these, 163 had been diagnosed with oesophageal or stomach cancer, while 172 were shown to be cancer-free after undergoing endoscopy tests.

The results, presented at the European Cancer Congress in Amsterdam, showed the test was both good at identifying patients who had cancer and unlikely to produce a false diagnosis.

Over the next three years, the researchers plan a larger trial.

The team is also working on breath tests for other types of cancer, such as those affecting the bowel and pancreas.