Scientists in Israel say they have devised a portable breath tester that detects lung cancer with 86% accuracy.
They say the device could provide an early warning system that flags the disease before tumours become visible in X-rays.
In a report in the journal Nature Nanotechnology, the researchers say the sensor uses gold nanoparticles to detect levels of so-called volatile organic compounds (VOC) -- measured in a few parts per billion -- that become more elevated in cancer patients.
Early detection of lung cancer dramatically increases the odds of survival.
Currently, only 15% of cases are discovered before the disease has begun to spread.