Genes account for half of testicular cancer risk

Gene mutations may account for as much of half the risk of developing testicular cancer, a study has suggested.

Researchers at the Institute of Cancer Research, London, and elsewhere, looked at population data from a Swedish family-cancer database consisting of 15.7 million people, 9324 of whom had been diagnosed with testicular germ-cell tumours, a common type of testicular cancer. They then examined the genetic data of nearly 6000 men, 986 of whom had testicular cancer, from two UK testicular cancer studies.

The combined findings revealed that a large number of as-yet-unidentified genetic mutations may be responsible for the heritability of testicular cancer. The researchers found that as much as 49 percent of the risk of testicular cancer could be down to genetic differences in DNA passed on from parents.

This data is particularly significant when compared with other cancers, where genetics is thought to be responsible for around 20 percent of risk. The researchers suggest that the inherited risk may come from a number of gene mutations rather than one single faulty gene, but only 9.1 percent of mutations associated with the risk of all testicular cancers have been identified so far.

The findings indicate there may be many more mutations that remain to be identified.

'Our study has shown that testicular cancer is a strongly heritable disease. Around half of a man's risk of developing testicular cancer comes from the genes he inherits from his parents,' said Dr Clare Turnbull, senior researcher at the Institute of Cancer Research.

Testicular cancer is one of the most common cancers in men. Testicular germ-cell tumours are particularly prevalent in young men, and cases in Western Europe have been on the increase over the past 40 years.

Previous studies have identified inherited gene variants located on chromosomes 5, 6 and 12, which together had been shown to lead to a fourfold increase in testicular cancer (reported in BioNews 511).

Further characterisation of these previously unknown DNA mutations could help in screening men to identify those most at risk of developing the disease.

Sam Gledhill, from the Movember Foundation Testicular Cancer Program, said: 'This is a significant development in the fight for a world where no man dies of testicular cancer.'

The work involved researchers from the UK, Germany, Sweden and the USA, and was published in Scientific Reports.