May 10, 2010

New Genetic Factors Linked To Breast Cancer

British scientists have a better understanding of the causes of breast cancer and improving treatments for it after a crucial discovery of five genetic factors linked to the risk of developing the cancer.

Douglas Easton from Britain's University of Cambridge, who led the largest genome analysis of breast cancer patients to date, scanned the gene maps of more than 16,500 patients and found five new common gene variations.

The findings bring the total number of common genetic variations linked to a small increased risk of breast cancer to 18. Scientists believe the new variations will help explain about 8 percent of the risk of getting the disease, according to Easton.

A few, high-risk gene variations that occur more rarely account for another 20 percent of breast cancer risk.

Breast cancer is the most common type of cancer in women in rich nations, killing about half a million people worldwide each year. In the UK, more than 45,500 women are diagnosed with breast cancer each year.

It is thought that nearly one in twenty of all breast cancers are linked to inherited faults in known genes. Family history is a well-known risk factor. Having a close relative with breast cancer nearly doubles a woman's risk for the disease. However, the precise reasons why a woman develops the disease are still unknown.

"This could lead to new genetic tests which may help identify women who have an increased risk of breast cancer due to inherited faults in genes," Dr Caroline Hacker, policy manager at Breakthrough Breast Cancer, told BBC News.

"Hereditary breast cancer is rare and only around one in 20 of all breast cancers are due to inherited faults in breast cancer genes," she added.

"Although there isn't anything we can do about the genes we inherit, we do know that you can reduce your risk of breast cancer by maintaining a healthy weight, limiting alcohol consumption and exercising regularly," she said.

Results of the study were published in the journal Nature Genetics on Sunday May 9.


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