London - Men most at risk from life-threatening prostate cancer can now be identified for lifelong monitoring following a genetic discovery by British scientists.
It raises the prospect of screening men to detect those predisposed to developing aggressive and potentially deadly tumours.
Scientists have found a total of 13 defects in genes that dramatically increase the chances of invasive prostate cancer.
They tested blood samples from 191 men with the disease who had three or more relatives also affected. Their findings show that some men have identifiable genetic profiles putting them at higher risk of prostate cancer – and these profiles also match a higher risk of an aggressive form.
It is hoped that men could be tested for gene mutations in the same way that women are currently screened for risky breast cancer genes, heralding a revolution in prostate cancer diagnosis and treatment.
While acknowledging that it was a small, “first-stage” study, Professor Ros Eeles, from London’s Institute of Cancer Research (ICR) and The Royal Marsden NHS Foundation Trust, said: “We proved that testing for known cancer mutations can pick out men who are destined to have a more aggressive form of prostate cancer.
“We already have the technical capabilities to assess men for multiple mutations at once, so all that remains is for us to do further work to prove that picking up dangerous mutations early can save lives. If so then in the future, genetic testing may be needed as part of the prostate cancer care pathway.”
Women with a strong family history of breast cancer are routinely tested for BRCA1 and BRCA2 gene defects, both of which greatly increase their chances of developing the disease. But the picture is much more complicated for prostate cancer, which seems to be linked to many different genetic mutations.
Currently there is no way of screening men who might be at risk from ferocious “tiger” prostate cancers that could cut short their lives, compared with slow-growing tumours that can safely be left untreated while their progress is monitored.
The ICR scientists found 13 “loss of function” mutations that prevented eight DNA repair genes from working properly.
Men with any of these mutations were much more likely to develop an invasive form of cancer that spreads elsewhere in the body, and to die from the disease.
The findings are reported in the latest edition of the British Journal of Cancer.
Co-author Dr Zsofia Kote-Jarai, from the ICR, said: “One of the important messages to come out of our study is that mutations to at least eight genes – and probably many more – greatly increase the risk of aggressive prostate cancer.
“Any future screening programme would need to assess as many of these genes as possible – more than we currently look for in women at risk of breast cancer, for example.”
Dr Iain Frame, Director of Research at Prostate Cancer UK, described prostate cancer diagnosis as a “minefield” and said the results of the ICR study were exciting.
“Current tests fail to differentiate between aggressive cancers that could go on to kill, and cancers that may never cause any harm,” he said. “Genetic testing to predict risk could revolutionise how we treat the 40 000 men diagnosed with the disease every year in the UK.” - Daily Mail