Genetic testing getting better at identifying testicular cancer risk

By Sally Robertson, B.Sc.Jun 13 2017

Testing for a new group of genes associated with testicular cancer has improved the ability to identify men at greatest risk of the disease, say researchers.

Scientists at The Institute of Cancer Research, London, found that by testing for 19 new genetic factors in addition to the 25 risk genes already known, they could identify the 1% of men at highest risk.

Men who inherited all 44 risk genes had a 7% lifetime risk of developing the cancer, which is 14 times higher than the 0.5% risk men in the general population have.

The findings raise the prospect of developing tests to screen men and find out whether they would benefit from monitoring and preventative treatment.

As reported in Nature Genetics, Clare Turnbull and team compared the DNA of more than 7,000 men who had testicular cancer with that of 23,000 men without the condition. Detailed reading of the DNA codes enabled the researchers to identify genetic changes that increased testicular cancer risk. They were also able to look at what was happening inside cells that would cause the changes to lead to cancer.

They found that many of the newly discovered genes interfered with how gene activity is regulated in cells. Of the 19 new changes, many affected how chromosomes are stabilised inside cells, for example.

“As well as picking out men at highest risk of testicular cancer, our new study also looks at the biology of disease, at what drives cells to become cancerous,” says co-author Paul Workman. “This should narrow the search for therapeutic targets and help researchers create new treatments for those men who stop responding to platinum chemotherapy.”

Workman says large-scale genetic studies such as this one are vital in defeating cancer, as the more that can be understood about the genetics behind it, the greater the possibility of selecting those most at risk and monitoring/treating them before they develop the disease.

"Although we are making good headway, there are more genetic changes that affect risk still to be found. Further studies are needed to understand how these genetic changes interact over time to influence the biology of the cell and lead to development of cancer," concludes Turnbull.