Cancer breath test underway

Progress is being made towards designing a cancer “breath test”, as researchers at the Technion (the Israel Institute of Technology) are working on an electric nose device to detect lung or head-and-neck cancer before symptoms appear.

Head-and-neck cancer is often detected too late for any treatment to be effective and the current ways to diagnose it require complicated specialist tests, making a non-invasive breath test for various cancers an appealing option.

Around 9,000 people in the UK are diagnosed with head-and-neck cancer each year, such as those of the eye, mouth, voice box and food pipe. The preliminary study, published in the British Journal of Cancer, used 82 volunteers, including 22 who had various head-and-neck cancers, 24 who had lung cancer and 36 who were healthy.

The breath test is essentially a nano artificial nose, which makes use of the chemicals emitted by the surface of cancer cells. The research found that sensors could be used to detect these chemicals in the breath. The sensor uses gold nanoparticles to detect levels of so-called volatile organic compounds that become more elevated in cancer patients. The test uses five sensors to detect five different volatile organic chemicals.

In the experiment, the sensor successfully distinguished between patients who had lung cancer, patients who had head-and-neck cancer, and healthy individuals, irrespective of their age, gender and lifestyle, such as smoking habits.

Even though this research is only in its early stages, and will be years before the test can be used in the clinic, it holds promise for an early diagnosis of these life-threatening diseases. Larger studies on wider samples will however be needed before the test can be considered fully reliable.

In addition to providing an early diagnosis of these cancers before tumours become visible in X-rays, the device could also be used to assess and monitor the effectiveness of cancer treatment and detect relapses earlier. Most GPs only see a few cancers in their career and diagnosis is difficult. Eventually, the aim is to be able to detect cancer instantly in a simple test at a stage where treatments have a good chance to succeed.