A saliva based DNA test to identify men who are at the highest risk of developing prostate cancer is to start early trials.
An international team of researchers led by scientists at The Institute of Cancer Research (ICR), London, have developed the new DNA test to unearth new genetic variants that were particularly hard to find.
The trials follow findings of a study of more than 140,000 men – published in the journal Nature Genetics [11 June 2018] – which identified 63 new genetic variations in the DNA code that increase the risk of prostate cancer.
Combining these genetic variants with more than 100 other genetic variants previously linked to the development of prostate cancer, the researchers have devised a new test to predict which men are most at risk of developing the disease during their lifetime.
Researchers said the test identifies one per cent of men who are at highest risk because they have inherited many of these risky variants – and they are nearly six times more likely to develop prostate cancer than the population average.
The study was largely funded by the National Cancer Institute in the US, with additional support from the European Research Council, Cancer Research UK, and Prostate Cancer UK.
Scientists at ICR now believe enough is known about prostate cancer genetics to begin assessing whether testing can benefit patients, and are planning a trial of a DNA test on saliva samples taken in GP practices. The trial will evaluate whether advice or preventative treatment could reduce cases of prostate cancer among those men found to have the highest inherited risk.
Researchers said that following the study, they can now account for almost 30% of a man’s inherited risk of prostate cancer which may be enough to start using the information in practical testing strategies.
Professor 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.”
Professor Paul Workman, chief executive of the ICR, added: “We are on the cusp of moving from theory to practice – from explaining how genetics affects prostate cancer risk, to testing for genetic risk and attempting to prevent the disease.
“This study also gives us important information about the causes of prostate cancer and the potential role of the immune system, which could ultimately be employed in the design of new treatments.”
Commenting on the proposed trial, Prostate Cancer UK said: “It has taken decades of research to uncover the complexity of prostate cancer genetics, so it’s good to see this coming close to having a benefit for men.”
