The test has produced encouraging results in a clinical study of 210 patients, and will now be tested in a larger trial involving three hospitals in London.
Oesophageal and gastric malignancies account for 15 per cent of cancer-related deaths globally.
Doctors diagnose oesophageal and gastric cancers by carrying out an endoscopy. This is a procedure 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 expensive. Moreover, only two percent of patients who are referred for an endoscopy by General Practitioners are diagnosed with oesophageal or gastric cancer.
“Our breath test could address these problems because it can help diagnose patients with early non-specific symptoms as well as reduce the number of invasive endoscopies carried out on patients, which often lead to negative results,” said lead author of the study George Hanna from Imperial College London.
“Diagnosis at an early stage could give patients more treatment options and ultimately save more lives,” Hanna noted.
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.
To take the test, patients breathe into a device similar to a breath alyser which is connected to a bag.
The compounds in their exhaled breath are analysed by a selected ion flow tube mass spectrometer.
The researchers used breath samples of patients with oesophageal and gastric cancer from 2011 to 2013.
The study was published in the journal ‘Annals of Surgery’.