A novel breakthrough global study has unearthed 72 more genetic variants responsible for increasing the risk breast cancer. The newly identified risk regions nearly doubles the total number of known variants associated with breast cancer, bringing the number to approximately 180. The findings published across two papers in Nature and Nature Genetics, are the result of work by the OncoArray Consortium.
The huge endeavour comprised 550 researchers from approximately 300 different institutions spanning across six continents. In total, the researchers analyzed the genetic data of 275,000 women. 146,000 of these women had been diagnosed with breast cancer.
One of the lead investigators on the study, Doug Easton (University of Cambridge, UK) commented: “These findings add significantly to our understanding of the inherited basis of breast cancer. As well as identifying new genetic variants, we have also confirmed many that we had previously suspected. There are some clear patterns in the genetic variants that should help us understand why some women are predisposed to breast cancer, and which genes and mechanisms are involved.”
Of the 72 newly identified genetic variants, 65 are common among women with breast cancer whilst the remaining seven mutations predispose women to developing estrogen-receptor-negative breast cancer.
The risk variants identified in the two studies are common: while some are carried by one woman in a 100, others are carried by more half of all women. Individually, the risks conferred by each variant are modest. However, because they are common and their effects multiply together, the combined effect is considerable.
The researchers believe these differences may be sufficient to change practice, such as in how women at different risks are screened.
“Using data from genomic studies, combined with information on other known risk factors, will allow better breast cancer risk assessment, therefore helping to identify a small but meaningful proportion of women at high risk of breast cancer,” explained Jacques Simard at Université Laval (Quebec City, Canada).
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Simard continued: “These women may benefit from more intensive screening, starting at a younger age, or using more sensitive screening techniques, allowing early detection and prevention of the disease. At the same time, this personalised information will also be useful to adapt screening modalities for women at substantially lower risk.”