Microscopic worms on a chip could be trained to sniff out cancer

By Clare Wilson.

Move over dog. A worm could be the next animal to help people find cancer.

Nematodes are attracted to compounds released by lung cancer cells. Early-stage work shows that when put into a small device, the nematodes wriggle towards the cancer cells.

The approach has promise for being turned into a diagnostic test for lung cancer that could potentially use urine or saliva samples from people.

Nematodes have a good sense of smell, which is important for them to sniff out their food, so other researchers are trying to train dogs to detect cancer. They are attracted to urine from people with cancer.

Cancer cells are different from non-cancerous cells in many ways. The odours from their favourite foods seem to be what attracts the nematodes.

The test kit consists of a small chip containing some of the 1-millimetre-long nematodes in a central chamber connected to two wells at opposite ends. A drop of liquid from a dish containing cancer cells is placed next to a well with liquid from non-cancerous cells next to it. Over the course of an hour, more nematodes moved towards the cancer cell liquid.

The tests showed that the device has an accuracy rate of 70%. This isn't high enough to be used as a medical test, but the accuracy is likely to improve if the nematodes are trained to respond to the floral scent.

The idea isn't as strange as it may sound, as nematodes have a surprisingly good memory for environmental smells.

The work was presented at the American Chemical Society meeting.