Four genetic studies into prostate cancer have uncovered new genetic variations associated with the disease. The information may be used to provide a more reliable indication of the risk a man has of developing prostate cancer.
Prostate cancer is the most common of the new cancers diagnosed in men, affecting around 35,000 men per year in the UK and killing just over 10,000. The current method for diagnosis using a blood test is unreliable; it often leads to further invasive and painful examinations for men who have no cancer, or gives the all clear to men who do have the disease.
These reports come from four separate research papers carried out in the UK, US and Iceland, published in the journal Nature Genetics, using genome-wide association studies and investigations looking at specific areas of the genome. Taken together, the results from the groups define nine new genetic variations that affect a man's lifetime risk of developing prostate cancer. The genes identified are not necessarily the underlying cause of the disease, but may lie in close proximity to genes that are responsible. The findings bring the total number of genetic variations firmly linked to prostate cancer to over 20, and increase the accuracy with which the disease risk can be predicted.
The scientists estimate that about one man in 100 carries most of these variants, which would roughly double his lifetime risk of developing the disease from about 10 per cent to about 20 per cent.
The UK groups were lead by Professor Doug Easton at the University of Cambridge and Dr Rosalind Eeles at the Institute of Cancer Research in Sutton, southwest London, and were funded by Cancer Research UK. Dr Kari Stefansson, chief executive of deCODE Genetics, an Icelandic company that sells genetic profiling tests directly to consumers, conducted the study in Iceland. They now sell a test that includes the new variants. Stefansson says: 'If our society really believes in screening programmes, then it would be really foolish not to include an instrument that can pick up this much risk'.
Dr Eeles says: 'Our study adds further compelling evidence that genetic factors can influence a man's risk of developing prostate cancer. These results will help us to more accurately calculate the risk that a man could develop prostate cancer which will enable more targeted screening. Understanding more about these genes could also lead to the development of new treatments'.
Dr Meredith Yeager from the National Cancer Institute led the study in the US. She says that 'further investigation is warranted to determine the molecular basis' of each of the prostate cancer associated variations found. Professor Easton agrees, saying that the work is 'all work in progress and there's lots more still to find, but it does seem that prostate cancer is more amenable than most diseases to this approach'. Further research into the clinical usefulness of these genetic tests is required before the NHS could offer such a service.
Further to this, two of the newly identified variants, NKX3.1 and ITGA6, could potentially be used for therapeutic targets, Dr Eeles said. For example, a group of drugs called HDAC1 inhibitors, which are already in clinical trials, may help men with defective NKX3.1.