London: Researchers have developed a new breath test that can diagnose esophageal and stomach cancers within minutes.
The test produced encouraging results in a clinical study, and will now be tested in a larger trial involving three hospitals in London.
Researchers analysed breath samples of 210 patients using the test. They found that the test can discriminate between malignant and benign oesophageal cancer in patients.
The test is 90 per cent accurate and provides results in minutes, which can take up to four to six hours to process using other methods. The test can also be applied to detect gastric (stomach) cancer tumours.
According to the researchers, economic modelling showed that the test could save the National Health Service (NHS) in UK 145 million pounds a year because it's cheaper, faster and easier to perform than other methods.
Doctors diagnose oesophageal and gastric cancers by carrying out an endoscopy where the inside of the body is examined using a probe with a light source and video camera at the end via the mouth and down the gullet.
However, the procedure is invasive and costs the NHS around 400-600 pounds per endoscopy.
The clinical study, published in the journal Annals of Surgery, was carried out by an international team led by scientists at Imperial College London and clinicians at Imperial College Healthcare NHS Trust.
Now, 400 patients at UCLH (University College London Hospitals NHS Foundation Trust), The Royal Marsden NHS Foundation Trust, and Guy's and St Thomas' NHS Foundation Trust will take part in a further trial.
The test looks for chemical compounds in exhaled breath that are unique to patients with oesophageal and gastric cancer.
The cancers produce a distinctive smell of volatile organic compounds (VOC), chemicals that contain carbon and are found in all living things, which can help doctors detect early signs of the disease.
Researchers were able to identify for the first time the number of VOCs in breath samples by using a selected ion flow tube mass spectrometer, an analytical instrument used to identify what chemicals are present in a sample.
This quantitative technology identified VOCs that were present at significantly higher concentrations in patients with oesophageal and gastric cancer than in non-cancerous patients.
The researchers said that the results could be used to set a biomarker, a biological feature used to measure the presence or progress of a disease.
To take the test, patients breathe into a device similar to a breathalyser which is connected to a bag. The compounds in their exhaled breath are analysed by a selected ion flow tube mass spectrometer.
Similar breath tests to discriminate between benign and malignant tumours exist but researchers said they have lengthy processing times and are unable to quantify the amounts of VOCs present in exhaled breath.
