Researchers have developed a new breath test to diagnose oesophageal and gastric cancer. The test has produced encouraging results in a clinical study, and the study was published in the journal Annals of Surgery.
Oesophageal and gastric malignancies account for 15 per cent of cancer-related deaths globally. Both cancers are usually diagnosed in the advanced stages because they rarely cause any noticeable symptoms when they first develop. As a result, the long-term survival rate can be very low. However, diagnosis of these cancers at an early stage can improve survival rates.
Researchers analysed breath samples of 210 patients using a new test. They found that the test can discriminate between malignant and benign oesophageal cancer in patients for the first time. 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.
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 say 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.