Huge study could lead to genetic screening for prostate cancer

Genetic screening for prostate cancer is now a real possibility following results from the largest-ever study into inherited risk factors for the disease. A clinical trial is likely to start this year as a result of the ground-breaking findings from an international group led by The Institute of Cancer Research, London, and the University of Cambridge, funded by Cancer Research UK and the European Commission.
The three-year study of 50,000 men (prostate cancer patients and controls without cancer) identified 23 new genetic variations associated with an increased risk of the disease. This raises the total discovered so far to 78. Significantly, 16 of the 23 newly discovered genetic changes are associated with the disease at its most aggressive and life-threatening.
None of the 23 genetic changes on its own raises a man’s risk of prostate cancer by more than a slight amount. But when a man has a number of the genetic changes these can combine to raise his risk significantly. With the genetic changes discovered, scientists can for the first time identify men who have inherited just over a 50% lifetime risk of developing prostate cancer.
Following these discoveries scientists now think they can identify the top 1% of men with the highest risk of developing prostate cancer who have 4.7 times the risk of the population average. It is these men who, it is hoped, will be identified by screening. They would then receive close monitoring in order that, if they do develop the disease, it is caught early when it is easier to treat. The way in which that screening would be conducted – for example, through blood tests or biopsies – will be indicated by the results of future clinical studies.
Study leader Professor Ros Eeles, Professor of Oncogenetics at The Institute of Cancer Research (ICR) and Honorary Clinical Consultant at The Royal Marsden NHS Foundation Trust, said: ‘These results are the single biggest leap forward in finding the genetic causes of prostate cancer yet made. They allow us, for the first time, to identify men who have a very high risk of developing prostate cancer during their lifetime through inheritance of multiple risk genetic variants. If we can show from further studies that such men benefit from regular screening, we could have a big impact on the number of people dying from the disease, which is still far too high.’
Over 40,000 men are diagnosed with prostate cancer in the UK each year, with almost 11,000 men dying from the disease. If it is caught early treatments are more effective, which is why identifying those most at risk, particularly from aggressive forms of the disease, is so important.
The team, from the ICR and the University of Cambridge, analysed 211,000 genetic variants from blood samples from 25,000 prostate cancer patients and compared them with those of a similar number of healthy men. The gene variants were analysed as part of the COGS (Collaborative Oncological Gene-environment Study) project, which publishes a series of research papers simultaneously today about the causes of prostate, breast and ovarian cancer. The Institute of Cancer Research