Genes inherited from parents play a more important role in determining whether a man develops testicular cancer than in most other forms of the disease, new research suggests.
Almost half of the risk (49%) of developing testicular cancer comes from men’s genetic code, according to an international study which included the UK’s Institute of Cancer Research (ICR).
This compared to around 20% genetic causation for other types of cancer.
Dr Clare Turnbull, senior researcher in genetics and epidemiology at the ICR, said: “Our study has shown that testicular cancer is a strongly heritable disease.
“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.”
Along with genetics, environmental and behavioural factors split the risk of developing cancer between them.
The study by UK, US, German and Swedish scientists, published in the journal Scientific Reports, analysed the risk of testicular germ cell tumours, the most common type of testicular cancer – in two different ways.
It used statistical analysis to examine patterns of ancestral testicular cancer in families in the 15.7 million people-strong Swedish Population Registry cancer family database, which included 9,324 cases of testicular cancer.
It then examined the genetic code of 6,000 British 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.
The scientists said the study, funded by the Movember Foundation, the ICR and Cancer Research UK is the largest to explore testicular germ cell tumours in detail.
Sam Gledhill, the Movember Foundation’s global manager for testicular cancer programmes, said: “These discoveries help to unlock the mysteries of this relatively poorly understood cancer and may ultimately identify potential treatment targets to fight this disease.”