A roundworm which can be found in raw fish such as Sushi can accurately detect cancer.

Roundworms successfully identify cancer in nine forms of the disease

A free-living roundworm that may be picked up by eating raw fish can detect cancer in people's urine, according to a study published in Plos One.

Researchers in Japan have found that Caenorhabditis elegans worms can accurately sniff-out cancer in the urine of patients with various forms of the disease, including stomach, breast and lung cancer.

They are now working with technology companies Johnan and Hitachi to turn the finding into a diagnostic test that can be used to diagnose the disease in its early stages.

Takaaki Hirotsu from Kyushu University, who co-led the work, said: "In existing tests, people must have different examinations according to the type of cancer they have. Our odour based-test detected all nine types of cancer we tested."

The researchers decided to investigate the cancer detecting ability of roundworms after encountering a 63-year old man with Anisakis larvae in his digestive system.  The worms had attached themselves to a small lesion in the man's stomach, which turned out to be the early stages of gastric cancer.

To find out whether the odour of the cancer lesion was attracting the roundworms, the researchers added drops of culture medium that cancer cells had grown in on one side of petri dishes.  On the opposite side they put drops of fresh culture medium. When they added C. elegans to the dishes, the worms moved towards the cancer medium.

Other kinds of cells were also grown in the medium, but the worms were not attracted to these. The researchers also took out the olfactory sense neurones in some of the worms, which stopped them moving towards the cancer side of the dish, suggesting that they are attracted by smell.

When placed nearby spots of urine from people with and without cancer, the worms were only attracted to the sample of the people with cancer.  Out of 242 samples, 24 of which had a cancer diagnosis, the worms correctly identified cancer 96 per cent of the time. The researchers say that this success rate is better than any blood test.

Out of 242 samples, 24 of which had a cancer diagnosis, the worms correctly identified cancer 96 per cent of the time - a success rate which is better than any blood test, the researchers say.

The worms successfully identified cancer in all nine forms of the disease they were exposed to - stomach, colorectal colon, oesophageal, pancreas, bile duct, prostate, breast and lung cancer.

The team are now looking to see whether different forms of cancer release different odours, and whether this has an effect in the worms. It is hoped that a commercial product will be ready by 2019.

Image (C) Mrmcdonnell