Breast cancer genetics revealed: 72 fresh mutations discovered in global study

The teams found that will 65 of the newly identified genetic variants are common among women with breast cancer.

The remaining seven mutations predispose women to developing a type of breast cancer known as estrogen-receptor-negative breast cancer, which doesn’t respond to hormonal therapies, such as the drug tamoxifen.

The fresh discoveries add to previous research bringing the total number of known variants associated with breast cancer to nearly 180.

Beyond BRCA1 along with BRCA2

The international team of 550 researchers across six continents, known as the OncoArray Consortium, included professor Doug Easton of the University of Cambridge, who led the investigation.

“Essentially, we used blood samples by a very large number of women (nearly 300,000), about half of whom had had breast cancer,” Easton explained in an email. Next, the researchers used the DNA by the samples to look for genetic mutations.

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“Think of a gene as a very long strand of DNA,” said Dr. Otis Brawley, chief medical officer of the American Cancer Society, who was not involved within the research. DNA is usually made up of nucleic acids, along with when a nucleic acid is usually incorrectly placed along the strand, This specific is usually referred to as a genetic mutation, noted Brawley.

Take BRCA1 along with BRCA2, two well-known genes that will confer a high risk of breast cancer when they contain mutations.

There are 125,950 base pairs within the BRCA 1 mutation, noted Brawley.

“Think of This specific as a 125,950 letter word,” said Brawley. “A mutation is usually a misspelling such that will the gene cannot code the proper protein.” A gene that will cannot code the proper protein leads to disease.

According to the National Cancer Institute, 55% to 65% of women who inherit a BRCA1 mutation along with around 45% of women who inherit a BRCA2 mutation will develop breast cancer by age 70.

However, the BRCA1 along with BRCA2 risk mutations, which are present in less than 1% of women, explain only a fraction of all inherited breast cancers.

The consortium came together, then, to discover the different causes of breast cancer susceptibility — the additional genetic mutations that will can lead to This specific form of cancer.

Finding the different mutations

The researchers measured DNA at over 10 million sites across the genome, said professor Peter Kraft of Harvard T.H. Chan School of Public Health, a study author.

Study sheds light on the 'different' breast cancer genes

“At each of these sites, we asked whether the DNA sequence in women with breast cancer was different than that will in women without,” said Kraft. “Because our study was so large, we could detect subtle differences between these two groups of women along with be sure these differences were not due to chance.”

According to Jacques Simard, a study author along with professor along with researcher at Universit√© Laval, Quebec City, the newly discovered mutations only slightly — by anywhere by 5% to 10% — increase a woman’s risk of developing breast cancer.

although even though, individually, these mutations don’t have as big as an effect as BRCA1 along with BRCA2 defects, there are many of them, so their “overall contribution is usually larger,” said Easton. An individual woman, then, may have two or more of these common smaller risk gene mutations, along with so her risk for developing breast cancer increases due to their combined effects.

Kraft noted that will “taken together, these risk variants may identify a tiny proportion of women who are at 3-times increased risk of breast cancer.” Women found to have several these smaller risk genetic mutations, then, could likely benefit by earlier mammography screening.

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Simard agreed, noting that will This specific may be time to “adapt” breast cancer screening guidelines based on This specific information instead of basing mammography guidelines on age alone. By doing so, Simard said, “we will detect a higher number of breast cancers.”

Quantifying cancer risk

Brawley described the fresh research as “not earth-shattering.” This specific is usually “most important for us nerds,” he said, although less so for the general public.

These types of studies help experts identify mutations that will “help us quantify the risk,” said Brawley. “This specific helps us figure out that will a non-patient, often a relative of a cancer patient, is usually at risk along with helps us quantify that will risk.” Normal lifetime risk of breast cancer is usually 12.5% for women within the US, said Brawley.

Lisa Schlager, vice president of community affairs & public policy for the nonprofit FORCE (Facing Our Risk of Cancer Empowered), said past studies along with evidence indicate that will about 10% of breast cancers are hereditary.

“This specific fresh information may mean that will that will estimate is usually low,” said Schlager.

This specific is usually important for patients to know whether their cancer is usually due to an inherited genetic mutation because they may be at increased risk of different cancers or their treatment recommendations may differ based on that will fact, said Schlager.

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“along with their family members may be affected with the same mutation,” said Schlager.

Enabling personalized medicine

For the promise of personalized medicine to be realized, our government along with health system need to “embrace the ability to use genetic information to tailor health care by providing affordable access to the needed screening along with preventive interventions,” said Schlager. As This specific stands today, men with BRCA mutations as well as some women may not be covered for screening by their insurance within the US.

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Brawley said “This specific type of genome wide screening has along with is usually being used to identify genes that will are associated with increased risk of several diseases, including diabetes, Alzheimer’s disease, stroke along with heart disease.”

“The same methodology can be used for different cancers,” said Easton. The screening method used by the consortium, the OncoArray, was designed to be used in many different cancer types, including prostate, ovary, colorectal along with lung cancer, he said.

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Simard added that will the cost of the genetic screen is usually “quite cheap,” at less than $50 per individual. “We can use just a blood sample or saliva sample. This specific’s not difficult to obtain the material for a genetic analysis,” he added.

Kraft said This specific was important to keep in mind that will the study was conducted primarily among women of European ancestry.

“For sure we have missed some variants associated with cancers that will are common in some non-European populations although rare in Europeans,” said Kraft. To find these, cancer genetic studies in Africans, African Americans, Latinas, Chinese along with different populations are ongoing, he added.

Easton commented that will most of the newly identified variants “are in regions of the genome that will regulate nearby genes.” These may someday serve as targets for fresh therapies or drugs to cure the disease.

within the end, the most important lesson here is usually the fact that will This specific research has been a collaborative effort, said Simard.

“Scientists are not in competition against each different,” he said. “We are definitely working together to expedite along with to accelerate the discovery.”

Breast cancer genetics revealed: 72 fresh mutations discovered in global study

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