A saliva test could identify the men most at risk of prostate cancer after a breakthrough in understanding the genetic causes of the disease.
Researchers at the Institute of Cancer Research, London will trial DNA saliva tests in 300 patients at three GP practices in the capital after finding 63 inherited triggers.
These are in addition to more than 100 genetic causes already known and enable scientists to pinpoint the one per cent of men who have nearly a six times greater risk than the male population of developing the disease.
Prostate cancer is the most common form of the disease in men and the third biggest cancer killer overall, after lung and colorectal, causing 11,800 deaths a year.
The current standard blood test for the disease is regarded as “flawed” and unable to save lives due to its lack of certainty. The spit-test will be expanded to 50 GP surgeries in London if the pilot scheme is successful.
The international study, led by the ICR and published in Nature Genetics today, compared the DNA code of almost 80,000 prostate cancer sufferers with more than 61,000 without the disease.
Each of the genetic changes had only a small effect on risk, but the combined impact of inheriting multiple variants could be “dramatic”, the ICR said. Those most at risk would have a 50 per cent chance of developing prostate cancer.
Ros Eeles, professor of oncogenetics at the ICR, said: “If we can tell from testing DNA how likely it is that a man will develop prostate cancer, the next step is to see if we can use that information to help prevent the disease.
“We now hope to begin a small study in GP practices to establish whether genetic testing using a simple spit-test could select high-risk men who might benefit from interventions to identify the disease earlier or even reduce their risk.”
Prasanna Sooriakumaran, a consultant prostate cancer surgeon at University College London Hospitals, said: “This new study shows that it is possible, using a simple spit test, to predict high-risk prostate cancer.
“This research could help avoid unnecessary and painful biopsies for millions of men, as well as highlight those men who need further testing. It represents a huge step closer to delivering personalised medicine.”