Five common genetic variants are newly associated with breast cancer risk, according to a report published online this week in Nature Genetics. All together, the 18 known common risk variants for breast cancer explain approximately eight percent of familial risk of breast cancer, while rare high-risk variants explain a further 20% of familial-related risk.
Breast cancer is the most common type of cancer in women from developed countries, causing approximately half a million deaths worldwide each year. Family history is a well-established risk factor for breast cancer; having a first-degree relative with breast cancer approximately doubles a woman's risk for the disease. Previous studies have identified 13 common genetic variants that are associated with increased risk of breast cancer.
In order to identify additional common risk variants for breast cancer, Douglas Easton and colleagues performed the largest genome-wide analysis of breast cancer patients to date. The authors analyzed the genomes of 16,536 patients and identified five genetic loci newly associated with breast cancer susceptibility.