Experts said it would be an “invaluable tool” in the battle against prostate cancer that could mark a whole new approach to tackling the disease.
Up to four in 10 European men have a genetic variation which raises their risk of prostate cancer by as much as 50 per cent.
Now scientists have discovered that the level of an easily detected protein in urine, called MSMB, is always lower in men who have this inherited genetic variation.
MSMB keeps the prostate healthy by killing imperfect cells that could turn cancerous, so men with lower levels of it are more likely to develop prostate cancer.
Currently there is no national screening programme for prostate cancer because the existing test cannot be used to forecast long term risk and is not accurate enough.
Levels of prostate-specific antigen (PSA) in the blood rise in response to the existence of cancer cells, but not beforehand.
PSA levels also rise if the prostate gland is enlarged, which limits its accuracy as a sign of cancer. Only one in three men with raised PSA actually have prostate cancer.
Additionally, there is no ‘normal’ level of PSA, making it unsuitable for a national screening programme.
By comparison there was a ‘normal’ level of MSMB and its presence remained largely unaffected by an enlarged prostate, said Dr Hayley Whitaker from Cancer Research UK’s Cambridge Research Institute, who led the study, published in the journal PLoS One.
Explaining the advantages of such a test, she said: “You could in theory test a man in his 20s or 30s and identify those at a higher risk of developing prostate cancer.
“We know that we can potentially reduce their risk by changing their diet and lifestyle.”
Those at a higher risk could also be more closely monitored through their lives to catch any developing cancer at an early stage, which increases survival chances significantly.
In practice she thought the test could be made available to 40-year-old men. Before that the incidence of prostate cancer is very low.
She added: “The protein is easy to detect because it is found in urine and would potentially be a very simple test to carry out on men to identify those most at risk of developing the disease. Men are just like women – they don’t like needles.”
Researchers from Cancer Research UK and the Institute of Cancer Research (ICR) in London are now testing 12 men at Addenbrook’s Hospital in Cambridge to see if the urine test works in practice. Results should be available by Christmas.
If all goes well Dr Whitaker said they could have regulatory approval within five years.
She said the cost also compared well to PSA – estimating it at £5.50 compared to £8.
Professor David Neal, prostate cancer specialist at Cancer Research UK’s Cambridge Research Institute, said: “This is a vital piece of research that could go a long way to find a long-awaited and much-needed reliable and easy test to identify those men most at risk of developing prostate cancer.
“If further studies show this marker can be used in the clinic this will be a landmark discovery.”
DR Kate Holmes, research manager at The Prostate Cancer Charity, said: “Given the known limitations of the PSA blood test, finding a technique to accurately diagnose prostate cancer is the Holy Grail of research into the disease, which is why these results are potentially exciting.
“An accurate, reliable urine test for prostate cancer would be an invaluable tool if it is proven to be successful on a large scale.”
Telegraph Uk