Nav: Home

Canadian researchers discover new genetic link to premenopausal breast cancer

June 20, 2019

University of Alberta researchers have added a new genetic marker to the breast cancer map, helping to expand the list of genetic mutations clinicians can watch for in cancer screenings.

The genetic marker--called rs1429142--was found to confer a higher risk of breast cancer in Caucasian women carrying the genetic variation compared to women without the variation. In premenopausal women, that risk reached as high as 40 per cent. The ability to identify those genes and their variants (called alleles) can be vital to early detection and life-saving treatment.

"This is important because the more we are able to create a complete picture of all the genes and all the variations and mutations that contribute to breast cancer, the closer we get to developing a genetic screen for breast cancer on a population level," said Sambasivarao Damaraju, a professor at the U of A's Department of Laboratory Medicine & Pathology and a member of the Cancer Research Institute of Northern Alberta. "If we can identify women at risk before they are diagnosed, and as long as we have the resources to mitigate that risk through preventative approaches, we can reduce the overall burden of breast cancer risk in a population."

Though the study primarily focused on genetic causes of breast cancer in Caucasian women, Damaraju's team went on to validate their findings in women of Chinese and African descent to explore the impact demographics may have on cancer risk.

Breast cancer is the most common cancer in women, with an estimated one out of every eight women expected to develop it in their lifetimes. While environmental factors like smoking, diet or lack of physical activity can lead to cancer, a person's genes also contribute to the risk of getting the disease.

"One of the real benefits of this research is that it brings a lot of focus to premenopausal breast cancer, which otherwise wasn't thought much about," said Mahalakshmi Kumaran, Damaraju's graduate student and first author on the paper.

The study, published in the International Journal of Cancer, is the first of its kind to examine breast cancer risk in Caucasian women divided into premenopausal and postmenopausal groupings. Because the majority of breast cancers are diagnosed in women over the age of 55, most genetic association studies focus on postmenopausal women. However, inherited forms of cancers, typically related to genetic mutations, are more likely to be more aggressive and be diagnosed earlier in life.

The researchers examined more than 9,000 women from Alberta for the study, utilizing samples from patients diagnosed with breast cancer and unaffected healthy controls from the Alberta Cancer Research Biobank and The Alberta's Tomorrow Project, respectively.

The DNA isolated from the participants' blood provided clues to specific chromosomes that showed links to breast cancer risk. Using those clues, the team began to zero in on the specific regions of the chromosome to locate genetic variations across samples. They noticed that rs1429142 showed a consistent association with breast cancer risk in multiple tests. When the data was analyzed based on menopausal status, the risk was shown to be significantly higher for premenopausal women.

After confirming the link between the genetic variant and breast cancer, the team then took the extra step of zooming in the genomic region to identify the specific location of the gene on the chromosome and marking it for future researchers.

"Finding this genetic marker is like starting with a high-resolution Google map of the world, and then slowly zooming in to the image of your house," Damaraju said. "It is valuable to do because now we have essentially planted a road sign on the chromosome that can help future researchers to carry out further in-depth studies."

Using international data from other genetic studies of breast cancer, and contributions from Vanderbilt University and St Jude Children's Research Hospital investigators from Tennessee, the team was also able to validate their findings in women of Chinese and African descent. They found that women of African descent were at a particularly high risk of premenopausal breast cancer as a result of the variant gene. This underlined the idea that genetic ancestry plays an important role in cancer risk.

While the study focused primarily on the genetic variation present on a single chromosome, Damaraju said they also found promising leads for identifying more cancer-related genetic markers on other chromosomes as well. In the future, he hopes to see his research contribute to a more precise method of treating breast cancer by tailoring therapies to the specific needs of the patient.

"My focus for the last 20 years has been to build a pipeline from genetic research to benefit the patient," he said. "We identify the genetic predispositions and focus on developing population-related risk models to enable potential screening of populations and eventually possible interventions."
-end-


University of Alberta Faculty of Medicine & Dentistry

Related Breast Cancer Articles:

Does MRI plus mammography improve detection of new breast cancer after breast conservation therapy?
A new article published by JAMA Oncology compares outcomes for combined mammography and MRI or ultrasonography screenings for new breast cancers in women who have previously undergone breast conservation surgery and radiotherapy for breast cancer initially diagnosed at 50 or younger.
Blood test offers improved breast cancer detection tool to reduce use of breast biopsy
A Clinical Breast Cancer study demonstrates Videssa Breast can inform better next steps after abnormal mammogram results and potentially reduce biopsies up to 67 percent.
Surgery to remove unaffected breast in early breast cancer increases
The proportion of women in the United States undergoing surgery for early-stage breast cancer who have preventive mastectomy to remove the unaffected breast increased significantly in recent years, particularly among younger women, and varied substantially across states.
Breast cancer patients with dense breast tissue more likely to develop contralateral disease
Breast cancer patients with dense breast tissue have almost a two-fold increased risk of developing disease in the contralateral breast, according to new research from The University of Texas MD Anderson Cancer.
Some early breast cancer patients benefit more from breast conservation than from mastectomy
Breast conserving therapy (BCT) is better than mastectomy for patients with some types of early breast cancer, according to results from the largest study to date, presented at ECC2017.
One-third of breast cancer patients not getting appropriate breast imaging follow-up exam
An annual mammogram is recommended after treatment for breast cancer, but nearly one-third of women diagnosed with breast cancer aren't receiving this follow-up exam, according to new findings presented at the 2016 Annual Clinical Congress of the American College of Surgeons.
Low breast density worsens prognosis in breast cancer
Even though dense breast tissue is a risk factor for breast cancer, very low mammographic breast density is associated with a worse prognosis in breast cancer patients.
Is breast conserving therapy or mastectomy better for early breast cancer?
Young women with early breast cancer face a difficult choice about whether to opt for a mastectomy or breast conserving therapy (BCT).
Breast density and outcomes of supplemental breast cancer screening
In a study appearing in the April 26 issue of JAMA, Elizabeth A.
Full dose radiotherapy to whole breast may not be needed in early breast cancer
Five years after breast-conserving surgery, radiotherapy focused around the tumor bed is as good at preventing recurrence as irradiating the whole breast, with fewer side effects, researchers from the UK have found in the large IMPORT LOW trial.

Related Breast Cancer Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...