Testicular cancer is cancer in one or both testicles, a part of the male reproductive system. A new study finds that 50% of the risk of getting the cancer comes from the DNA passed down from our parents.
Scientists at The Institute of Cancer Research (ICR) and colleagues in Europe and the U.S used two different ways to analyze the risk of testicular germ-cell tumors - the most common type of testicular cancer.
One way explored the history of the disease in families across 15.7 million people. This Swedish database included 9,324 cases of testicular cancer.
The scientists then conducted a detailed analysis on the genetic code of almost 6,000 U.K. men from two previous studies, 986 of whom had been diagnosed with the disease.
The combined analysis showed that about 49% of all the possible things contributing to testicular cancer risk are inherited.
The researchers noted that the inherited risk comes from a large number of minor mutations in DNA code, rather than one faulty gene with a big effect. However, only 9.1% of the gene mutations that can cause testicular cancer have been identified so far.
"Around half of a man's risk of developing testicular cancer comes from the genes he inherits from his parents -- with environmental and behavioral factors contributing to the other half," says Dr. Clare Turnbull, senior researcher in genetics and epidemiology at the ICR, in a statement.
Dr. Turnbull adds, "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."