Transmissible cancer is a strange form of the disease. Unlike any other type of cancer it is not caused by an individual’s own cells growing uncontrollably. It’s an infectious cancer – it’s a cancer dogs can catch.
It first arose in an animal who lived about 8,000 years ago. Cells from this animal, termed the ‘founder dog’, were passed on to other dogs. The cells somehow survive, evading the immune system of new animals, continuing to grow and form tumours.
The tumours are contagious, sexually transmitted, and have spread around the world. Genomic analysis has shown that wherever there are populations of stray dogs - from the deserts of Africa to the Himalayas to the Australian Outback – there are these tumours. Each one carries descendants of the cells from the founder dog.
In essence, the tumour is a parasite, being passed from host to host. Little is understood about its biology – for example no-one knows exactly how it escapes the immune system. Alex is working with Elizabeth Murchison, a group leader at the University of Cambridge who studies transmissible cancers. The aim was to collect samples for genomic analysis – to see if the radiation has any effects on the cancers.