UK scientists identify first testicular cancer risk genes
Scientists at The Institute of Cancer Research (ICR) have identified the first inherited genetic risk factors for testicular cancer, a disease that affects around 2,100 men every year in the UK.
The team compared the genes of 730 men with testicular cancer against those of healthy men.
They found that many of the men who had developed testicular cancer had particular genetic variants on chromosomes 5, 6 and 12 that were not shared by the healthy men.
The strongest of the three genetic factors increases a man's risk of developing the disease by two to threefold, while individuals who inherit all three of the variants face up to four times higher risk.
Publishing their findings in the journal Nature Genetics, the researchers suggest that they raise the possibility of a screening test to identify men whose genes place them at an increased risk for the disease.
Dr Elizabeth Rapley, one of the lead scientists at the ICR, commented: "We have known for some time that men whose father, brothers or sons had testicular cancer are much more likely to get it themselves and we have been searching for this genetic link.
"In this research, we have identified three genetic factors linked to an increased risk of testicular cancer. We believe there are more still to be found and we are working on identifying the rest."
Professor Mike Stratton, from the Wellcome Trust Sanger Institute and the ICR, noted that the risks conferred by each gene "add together to some extent".
"By combining these genetic risks with other known risk factors it may be possible in future to identify men who are at high risk of developing testicular cancer, particularly those who have a brother or father already affected by the disease. This may allow early detection or prevention," he said.
The study was funded by the Everyman Campaign - which seeks to raise awareness of testicular cancer and prostate cancer - as well as Cancer Research UK and the Wellcome Trust.
Researchers hope that the discovery may also shed light on the development of testicular cancer as the three genetic variants all occur near genes that are involved in a biochemical pathway required for the survival and development of cells that go on to form sperm.
Dr Rapley said that the team hopes to improve treatment options by furthering their understanding of the biology of the disease.
She also noted that the researchers are continuing to look for more genetic risk factors and are seeking to recruit up to 3,000 men who have had testicular cancer for their study.
"We are grateful to all those men who have participated in this study so far and would like anybody who has suffered testicular cancer to contact us - even if they were treated 20 years ago," Dr Rapley revealed.
"They could ultimately help us develop treatments and improve diagnostic techniques to improve the lives of sufferers in the future."
Ed Yong, Cancer Research UK's health information manager, said: "While more than 95 per cent of testicular cancer patients are successfully treated, finding genes that increase the risk of this cancer is important.
"It tells us more about its basic biology and presents new opportunities to prevent, diagnose and treat the disease in those men most at risk - men aged under 50."
Rapley, E., Turnbull, C., Al Olama, A., Dermitzakis, E., Linger, R., Huddart, R., Renwick, A., Hughes, D., Hines, S., Seal, S., Morrison, J., Nsengimana, J., Deloukas, P., Rahman, N., Bishop, D., Easton, D., & Stratton, M. (2009). A genome-wide association study of testicular germ cell tumor Nature Genetics DOI: 10.1038/ng.394