Scientists identify four more Breast Cancer Genes

Four genetic mutations that double the risk of breast cancer in women have been discovered by several teams around the world, raising hope of developing new methods to treat younger women with higher risk of developing breast cancer.

In their research, published online in the journals Nature and Nature Genetics, scientists said that they have identified mutations in four genes, called FGFR2, TNRC9, MAP3K1 and LSP1, which were more common in the people with breast cancer.

Faults in these genes augment the risk of developing breast cancer significantly. Up to 60% of U.S. women probably carry at least one of the mutations in one of the genes, called FGFR2, the researchers said.

The findings may prove to be a major breakthrough genetic discoveries relating to breast cancer genetics since the identification of the BRCA1 and BRCA 2 susceptibility mutations in 1994, they said.

Mutations in BRCA1 gene are associated with 50% to 85% life-time risk of developing breast cancer as seen in various studies. Women carrying BRCA1 gene mutation often develop breast cancer at a younger age compared to the general population. These genes, which cause a quarter of hereditary cases, are rare, and account for less than 10% of breast cancer cases.

Contrary to the genetic variations associated with familial breast cancer, two of the four new genes are relatively common. According to Cancer Research UK, which helped to fund the study, an estimated one in six and one in 16 women carry two faulty copies of one of these genes. The three other genes found in the study are also common among the population but carry a lower risk of disease

The latest study, conducted by several teams of scientists, was led by Douglas Easton, a professor of cancer epidemiology at Cambridge University in the UK. To reach their findings, Easton along with the fellow researchers studied the DNA of nearly 50,000 women, half of whom had breast cancer.

David Hunter of Harvard University and a team at the U.S. National Cancer Institute looked at more than 2,200 women of European ancestry, while a team from the bio-pharmaceutical firm, deCODE Genetics, the University of Nijmegen in the Netherlands and elsewhere examined 22,000 people to identify other gene mutations associated with breast cancer.

A team of Australian, US, Asian and European scientists used "DNA chips" to examine each participant's genome for genetic variations that were found to be strongly tied with breast cancer. "We're very excited by these results because the regions we identified don't contain previously known inherited cancer genes," Prof. Easton said.

"This opens the door to new research directions. Only very recent advances in technology have allowed us to carry out such a large comparison study," he said.

Breast cancer is one of the most common forms of cancer among women striking about 1 million women a year worldwide. It affects nearly 44,000 women in U.K. every year. According to the American Cancer Society estimates, nearly 212,920 new cases of the disease were diagnosed in the U.S. in 2006, while over 360,000 new cases of breast cancer are diagnosed in Europe every year.

World Health Organization (WHO) estimates that breast cancer engulfs 500,000 lives a year globally.