Volatile organic compounds (VOC) are a tiny telltale in the breath of cancer patients. Oncologists are interested in VOC testers because they offer the possibility of non-invasive screening for a disease that, tragically, is often spotted too late. A device that would be cheap, portable and also pinpoint precursor conditions would be especially welcome.
For patients with suspected stomach cancer, a useful breath test would avoid the discomfort of an endoscopy. Researchers at the Israel Institute of Technology have designed a low-cost electronic device that uses gold nano-particles to detect stomach cancer molecules in the breath. The device can also spot signatures of lesions that herald the disease.
Researchers compared the nano-array device against the benchmark for VOC assessment, a more complex and expensive lab technique using gas chromatography and mass spectrometry. Each method was used to screen breath samples taken from 484 study participants in Latvia, 99 of whom had already been diagnosed with stomach cancer but had not yet been treated for it. Both the methods accurately spotted those with the cancer, as well as the 'breath prints' of high-risk patients who had lesions that often develop into gastric tumors.
However, experts have raised concerns over the accuracy of the test, as the telltale amounts are only 10 particles per billion or less in a sample of exhaled breath. They have also suggested that further trials should be conducted to confirm whether a precursor condition actually developed into cancer, in order to avoid unnecessary treatment.
The study is published in the Gut