About 8000 people in the UK develop a cancer in their oesophagus - the tube that connects the back of the throat to the stomach - every year. The majority of these people have detectable changes in the cells lining the oesophagus for many years before they develop the cancer. These changes are referred to as "Barrett's oesophagus". But only a minority of people with Barrett's, which is actually relatively common, will actually go on to develop cancer, which makes screening for the disease an expensive headache. Now Rebecca Fitzgerald, a physician from Cambridge, has developed a sponge - packed into a pill - on the end of a string - that can be swallowed, and then retrieved, bringing with it a sample of cells from the full length of the oesophagus. The DNA profile of these cells can then be used to pinpoint danger signs pointing towards a developing cancer. Chris Smith spoke to Rebecca Fitzgerald to find out more...