British scientists have found three new genetic risk factors for testicular cancer, the most common form of the disease in young men, and say their findings should aid efforts for better treatments and earlier diagnosis.
A research team led by the Institute of Cancer Research scanned the gene maps of almost 6,000 men, some with and some without testicular cancer, and found genetic variants in three genetic regions were significantly more common in the cancer patients.
"The genes located in these regions give us clues to the mechanisms by which testicular cancer develops," said Nazneen Rahman, an ICR professor who worked on the study. "In time this may allow us to develop new treatment options."
The team confirmed their findings by analyzing another 670 testicular cancer patients and 3,500 men without the disease.
The results, published in the journal Nature Genetics on Sunday, take the number of genetic regions associated with testicular cancer risk to six, after earlier studies identified others.
"This study represents further, important progress toward identifying men who are at increased genetic risk of testicular cancer," said Clare Turnbull, who led the study.
"Finding those men at highest risk may allow early detection or prevention of the disease."
Testicular cancer is the most common cancer in men aged 15 to 45 years. It is considered one of the most treatable cancers because it usually responds well to chemotherapy, but survivors often have fertility problems after treatment.
The disease has a strong genetic component and men who have a brother affected by testicular cancer have an eight- to tenfold increased risk of developing the disease than men with no family history. These inheritance risks are much higher than in other cancer types, which are generally only two-fold.
The three genes identified by the British team are called TERT, ATF7IP and DMRT1.
Turnbull and colleagues explained in their study that TERT and ATF7IP were important in maintaining the correct length of the ends of chromosomes, which are called telomeres.
Shortened telomeres are known to occur in many cancers and genetic variants in TERT have already been linked to other cancers, including lung, bladder, cervical, pancreatic, skin and prostate cancer.
The third gene found in this study, DMRT1, plays an important role in sex determination and has been implicated in the development of testicular cancer in mice.