Scientists eavesdrop on spread of cancer

In collaboration with the Press Association

Scientists have managed to detect skin cancer cells by literally listening to the sound they make when hit by a laser.

The technique is extremely sensitive but so far has only been used to detect cancer cells in a salt-water solution.

But its developers say it could one day allow doctors to detect migrating cancer cells before they reach other organs, greatly speeding up the process of detection and diagnosis.

The technique relies on a phenomenon known as "photoacoustics".

This combines laser and ultrasound technology. Laser pulses are fired into samples, which are then absorbed by the melanin pigment in melanoma cells. This causes the melanin granules to heat up rapidly, and emit an ultrasonic "crack".

This distinctive noise far outside the range of human hearing but detectable with special microphones ? allowed the researchers to instantly determine whether cancer cells were present in the sample.

Work is also currently being conducted to try to adapt the method for use in other forms of cancer. The study was carried out by the University of Missouri-Columbia and published in the journal Optics Letters.