Breath analysis is a method of diagnosing and monitoring human diseases non-invasively by detecting volatile organic compounds (VOCs) in exhaled breath. VOCs are carbon-containing compounds that are sufficiently volatile to be detectable in the gas phase at room temperature. Different diseases produce different patterns of VOCs, which can be detected using gas chromatography-mass spectrometry (GC-MS).
Patients breathe into a collection device for a few minutes. The exhaled breath is captured on thermal desorption (TD) tubes, which are then transported to our dedicated VOC laboratory at Imperial College London's Hammersmith Campus. The samples are analysed using thermal desorption gas chromatography time-of-flight mass spectrometry (TD-GC-TOF-MS), which can detect VOCs at concentrations at low concentrations.
Our research spans five major gastrointestinal cancers: oesophageal, gastric, pancreatic, liver (hepatocellular carcinoma and cholangiocarcinoma), and colorectal cancer. We have also expanded into neurological conditions including Parkinson's disease (PANORAMA) and epilepsy (VIBES), as well as oesophageal cancer survivorship (MAPLES).
Our biomarker discovery results show strong diagnostic performance: oesophageal & gastric cancer, colorectal cancer, pancreatic cancer, and liver cancer. These results are now being validated in large-scale multicentre clinical trials.
Our trials recruit patients who are being investigated for symptoms that could be related to gastrointestinal cancers. Recruitment takes place through participating NHS centres, you cannot self-refer directly to the research team. If you are experiencing symptoms and think you may be eligible, please speak with your GP or hospital clinician who can refer you through the appropriate NHS pathway. If your hospital is a participating centre, the clinical team there will be able to discuss the study with you.
The breath test is currently a research tool being validated in clinical trials. It is not yet available as a routine NHS diagnostic test. Our aim is to complete the validation process and translate the breath test into routine clinical practice in primary care. Health economic modelling suggests that a breath test pathway for oesophagogastric cancer would save the NHS money annually compared to the current pathway.
The test is non-invasive, painless and takes only a few minutes. In the MAGIC study of 1,002 patients, 99% found breath testing easy or very easy. There is no preparation required beyond a minimum fasting period.