Almost half of the risk of developing testicular cancer comes from the DNA passed down from our parents, much more than in most other cancer types, a new study reports.
In other cancers, genetics account for less than 20% of risk.
“Our study has shown that testicular cancer is a strongly heritable disease,” said Dr Clare Turnbull, Senior Researcher in Genetics and Epidemiology at The Institute of Cancer Research.
“Around half of a man’s risk of developing testicular cancer comes from the genes he inherits from his parents – with environmental and behavioural factors contributing to the other half.
“Our findings have important implications in that they show that if we can discover these genetic causes, screening of men with a family history of testicular cancer could help to diagnose those at greatest risk, and help them to manage that risk.
“But our study also shows that much work remains to be done. There are a lot of genetic factors that cause testicular cancer which we are yet to find – so the first step must be to identify the genetic drivers of testicular cancer so we can develop new ways to prevent it.”
The scientists at The Institute of Cancer Research along with colleagues in Germany, Sweden and the US, published their report in the journal Scientific Reports. Their work was funded by the Movember Foundation, The Institute of Cancer Research (ICR) and Cancer Research UK.
It is the largest study ever to explore testicular germ cell tumours in detail.
Researchers first used statistical analysis to examine patterns of ancestral testicular cancer in family groups across 15.7 million people from the Swedish Population Registry cancer family database, including 9,324 cases of testicular cancer.
They then looked in detail at the genetic code of 6,000 UK men from two previous testicular cancer studies, 986 of whom had been diagnosed with the disease.
The combined analysis revealed that 49% of all the possible factors contributing to testicular cancer risk are inherited.
It found that the inherited risk comes from a large number of minor variations in DNA code, rather than one faulty gene with a big effect.