Scientists are developing a 10-minute cancer test that can be taken at home using just a drop of saliva.David Wong, a professor of oncology at the University of California, Los Angeles, says it is possible to detect tumour DNA in bodily fluids by means of a "liquid biopsy".The test looks for genetic mutations in blood plasma that are consistent with a tumour.The saliva test is 100% accurate and is so simple that it could be carried out at a pharmacy or a dental clinic or by someone on his own, he claims. Currently scientists can use blood tests to detect cancer only if they have taken a biopsy and sequenced a tumour to discover which genetic signature to look for.Wong's test has shown that a drop of saliva contains enough data to give a definitive diagnosis as soon as a tumour develops, he said.The test is non-invasive, costs around R350 and will enter full clinical trials with lung cancer patients later this year.Wong expects the test to be approved within two years by the US Food and Drug Administration. He hopes it will be generally available worldwide by the end of the decade...