Eighty percent of people suffering from lung cancer die within a year after diagnosis, as the disease is identified only in the advance stages. According to Dr Peter Mazzone it is very it crucial to detect lung cancer timely since it is often silent in its early stages, making it difficult to pick up at a stage when it could be treated effectively. US scientists have devised a colour test which shows up unique chemical changes in the breath of people with lung cancer. The hues of a series of 36 dots detect lung cancer accurately in just under three out of four people with the disease said the researcher. The concept of a "gas fingerprint" for lung cancer is not new, but the kit is. The sensor, which is slightly bigger than a quarter dollar or a two pound coin, is inexpensive and easy to use. Experts have known for many years that the chemical composition of a person's breath changes when they develop lung cancer. This is because lung cancer cells give off chemicals, called volatile organic compounds or VOCs, which are then breathed out. The previous highly sensitive machine was not only expensive but also required specially trained experts to interpret the results.

The researchers used the colour sensor to test the breath of 122 people with different types of lung disease, including 49 with cancer, and 21 healthy people. It was able to accurately predict the presence of cancer in just under three out of four of those with lung cancer, including very early tumours.
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