A device that uses tiny worms to sniff out lung cancer could help save lives by detecting the disease before it spreads. The worms are drawn to the floral smell of cancer cells which likely resemble their favourite food, according to a new study.
More than 160,000 people die of cancer in the UK every year, with breast, prostate and lung cancer being the most common types. But those who are diagnosed with the disease early - stage one, before it has spread to other parts of the body, have a much higher chance of survival.
Currently, lung cancer is diagnosed by imaging tests or biopsies, but these tests cannot detect tumours at their earliest stage. While dogs can be trained to sniff out cancer in human breath, or blood and urine samples, keeping them in a medical lab is not practical. Now scientists at the Myongji University in Korea have enlisted the help of a much smaller creature, a worm called C. elegans, which can also detect the disease. Dr Shin Choi, a lead author of the study, said: "Lung cancer cells produce a different set of odour molecules than normal cells.
"It’s well known that the soil-dwelling nematode, C. elegans, is attracted or repelled by certain odours, so we came up with an idea that the roundworm could be used to detect lung cancer." A silicone chip with wells on either end connected to a central chamber by channels was placed in a Petri dish by the researchers.
They added a solution containing lung cancer cells at one end of the chip and normal cells at the other. Worms placed in the central chamber were more likely to move towards the lung cancer cells, the researchers found. Based on their tests, the device was around 70 per cent effective at detecting the cancer cells.
Further tests with the chip revealed what specific odour molecules had attracted the worms to the cancer cells. They discovered the worms were attracted to a volatile compound known as 2-ethyl-1-hexanol which gives off a floral scent. Dr Choi added: "We don’t know why C. elegans are attracted to lung cancer tissues or 2-ethyl-1-hexanol, but we guess that the odors are similar to the scents from their favourite foods."
They are now hoping to increase its accuracy by using worms which have already been exposed to cancer cells and therefore know what they smell like. Once perfected, the researchers are hoping to extend their testing on urine, saliva and even breath from cancer patients. Dr Choi said: "We will collaborate with medical doctors to find out whether our methods can detect lung cancer in patients at an early stage." The findings were presented at the American Chemical Society (ACS).
