A Breakthrough Study Reveals 72 New Breast Cancer Gene Variants

It is now believed that a simple blood test could identify women at greater risk of breast cancer to establish much earlier diagnosis. Researchers from around the world have discovered 72 gene mutations which have not been known previously that can lead to the development of breast cancer. The studies describing the work have been published in the Journals Nature and Nature Genetics. To find these genetic variations, 550 researchers from around 300 institutes in 6 continents analyzed data take from nearly 275000 women. There were 122,977 cases and 105,974 controls of European ancestry and 14,068 cases and 13,104 controls of East Asian ancestry.

Two genes already commonly associated with breast cancer are BRCA1 and BRCA2. The researchers discovered nine more variations affecting the gene BRCA1, which popularly caused Hollywood actress Angelina Jolie to have a mastectomy after finding out that she carried the gene. In total, they confirmed 107 genetic variants and 72 new ones. The discovery allowed the team to calculate that one in 10 women have a 70 per cent higher risk of getting breast cancer.

It was found that 65 of the newly identified genetic variants were same in women with breast cancer. The remaining 7 mutations predispose women to develop a different kind of a breast cancer which is called estrogen-receptor-negative breast cancer. This is a kind that doesn't respond to hormonal therapies. This takes the total number of known variants associated with breast cancer to nearly 180.

As per National Cancer Institute, 55% to 65% of women who inherit a BRCA1 mutation and around 45% of women who inherit a BRCA2 mutation will develop breast cancer by age 70. But the BRCA1 and BRCA2 risk mutations (present in less than 1% of women) give explanation for a part fraction of all breast cancers which have been inherited. The consortium came together to find out the other reasons of breast cancer chances - genetic mutations which are additional that can lead to this kind of a cancer.

 

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