Study finds genetic variants linked to an increased risk of developing brain cancer

An international team of researchers, including scientists from the United Kingdom's Institute of Cancer Research and the University of Texas MD Anderson Cancer Center, have identified five common gene variants that indicate increased risk for developing the most common form of brain cancer, glioma. Their study, which was funded in part by the Wellcome Trust, first involved comparing the DNA of more than 1,800 people with the disease to healthy people living in the UK and the USA. Researchers then sought to confirm their results by studying an additional 2,545 confirmed cases of glioma and approximately 3,000 healthy Europeans.

The investigators learned that the more gene variants that an individual carries, the more likely they are to develop glioma. With humans carrying two copies of each gene, their genome could include a total of ten of the five glioma variants. Compared to the general population, the researchers found that people with eight or more of the genetic variant are three times more likely to get the deadly disease, and people with a relative diagnosed with brain cancer are twice as likely to develop the disease. Moreover, recent genetic research has shown that most cancers are triggered by many genetic factors - not just one or two genetic mutations, with each factor raising the risk of cancer slightly.

"We've found the first real evidence that variations in the genes which many people carry can increase their risk of this deadly disease," says Professor Richard Houlston from the Institute of Cancer Research, lead researcher on the study. Houlston and his colleagues believe that the new variants are responsible for up to 14 percent of the inherited risk of glioma. In addition, the study provided new insights into how the disease develops, with some of the genetic regions found associated with other genes previously linked to cancer development. The hope is that their research may lead to new biological targets for treatment.

Gliomas are the most common type of primary brain tumor. According to the American Brain Tumor Association, primary brain tumors occur at a rate of 12.8 per 100,000 people. Although people of all ages can develop brain tumors, the problem appears to be most prevalent in children ages 3 to 12 and in adults ages 40 to 70. In the United States, approximately 2,200 children younger than age 20 are diagnosed each year with brain cancer. The disease is especially difficult to treat, making it one of the most deadly forms of cancer.

News Release: Study identifies first gene links to most common brain cancer http://www.wellcome.ac.uk/News/2009/News/WTX055766.htm July 6, 2009