Nav: Home

Large data set brings precision to breast cancer diagnosis and care

May 04, 2017

Although the odds of developing breast cancer are nearly identical for black and white women, black women are 42 percent more likely to die from the disease. This mortality gap - driven by social and environmental, as well as biological factors - continues to persist.

A large, multi-institutional study, published on-line May 4, 2017, in JAMA Oncology, was designed to understand this gap by beginning to unravel the germline genetic variations and tumor biological differences between black and white women with breast cancer. This is the first "ancestry-based comprehensive analysis of multiple platforms of genomic and proteomic data of its kind," the authors note.

Findings from this study could lead to more personalized risk assessment for women of African heritage and hasten the development of novel approaches designed to diagnose specific subtypes of aggressive breast cancers early and treat them effectively.

One new finding is that black women with hormone receptor positive, HER2-negative breast cancer had a higher risk-of-recurrence score than white women. The study also confirmed that black patients were typically diagnosed at a younger age and were more likely to develop aggressive breast-cancer subtypes, including basal-like or triple-negative cancers (tumors lacking estrogen receptors, progesterone receptors and HER2), as well as other aggressive tumor subtypes.

"People have long associated breast cancer mortality in black women with poverty, or stress, or lack of access to care, but our results show that much of the increased risk for black women can be attributed to tumor biological differences, which are probably genetically determined," said study author Olufunmilayo Olopade, MD, professor of medicine and human genetics at the University of Chicago.

"The good news," she said, "is that as we learn more about these genetic variations, we can combine that information with clinical data to stratify risk and better predict recurrences - especially for highly treatable cancers - and develop interventions to improve treatment outcomes."

"This is a great example of how team science and investments in science can accelerate progress in identifying the best therapies for the most aggressive breast cancers," said co-author Charles Perou, PhD, a member of the University of North Carolina Lineberger Comprehensive Cancer Center and professor of genetics, and pathology & laboratory medicine at the UNC School of Medicine.

"In the largest dataset to date that has good representation of tumors from black women, we did not find much difference between the somatic mutations driving tumors in black and white women," he added. "Yet black women were more likely to develop aggressive molecular subtypes of breast cancer. Now we provide data showing that differences in germline genetics may be responsible for up to 40 percent of the likelihood of developing one tumor subtype versus another."

The study used DNA data collected from 930 women - 154 of predominantly African ancestry and 776 of European ancestry - available through The Cancer Genome Atlas (TCGA), established by the National Cancer Institute and the National Human Genome Research Institute. The researchers combed through the data methodically, looking for racial differences in germline variations (normal DNA), somatic mutations (tumor acquired), subtypes of breast cancers, survival time, as well as gene expression, protein expression and DNA methylation patterns.

"Most significantly," explained first author Dezheng Huo, MD, PhD, associate professor of public health sciences at the University of Chicago, "we observed a higher genetic contribution to estrogen-receptor negative breast cancer in blacks."

Black women were more likely to get these highly aggressive cancers. This is one of the first studies to connect genetics to this racial difference in tumor subtype frequencies.

The study also revealed 142 genes that showed differences in expression levels according to race. One gene, CRYBB2 (Crystallin Beta B2), was consistently higher in tumors from black patients within each breast cancer subtype, as well as in normal tissues, suggesting it may be a race-specific gene.

The researchers also found somatic mutations in 13 genes or DNA segments that differed in frequency in tumors from black and white women. One of them, a mutated gene called TP53, was more common in black women (52%) than white women (31%) and was a strong predictor of disease recurrence.

"Despite the relatively short follow-up time in the TCGA dataset, we were able to detect a significant racial disparity in patient survival using breast cancer-free interval as the endpoint between patients of African and European ancestries," said co-first author Hai Hu, PhD, vice president for research at the Chan Soon-Shiong Institute of Molecular Medicine at Windber. "Most of the worst outcomes came from basal-like subtype breast cancer patients of African Ancestry."

"Black women in all categories, including the most common breast cancers, were likely to have a worse prognosis," Olopade said.

"Understanding the basic, underlying genetic differences between black and white women, the higher risk scores and the increased risk of recurrence should lead us to alternative treatment strategies," said Perou.

The crucial long-term benefit of this study, according to Olopade, is that "it is a step toward the development of polygenic biomarkers, tools that can help us better understand each patient's prognosis and, as we learn more, play a role in choosing the best treatment."

"Genes matter," she added. "This is a foot in the door for precision medicine, for scientifically targeted treatment."

"This study now outlines a path for us to personalize breast cancer risk assessment and develop better strategies to empower all women, especially black women, to know their genetics and be more proactive in managing their risk," Perou said.
-end-
The study was funded by the National Cancer Institute, the Breast Cancer Research Foundation, Susan G. Komen Foundation for the Cure, the American Cancer Society and the U.S. Department of Defense. Also contributing were Toshio Yoshimatsu and Jason Pitt from the University of Chicago; Katherine Hoadley and Melissa Troester of the University of North Carolina at Chapel Hill; Jianfang Liu, Yuanbin Ru, and Lori Sturtz from the Chan Soon-Shiong Institute of Molecular Medicine at Windber, Windber, PA; Suhn Rhie of the University of Southern California; Eric Gamazon of Vanderbilt University; Andrew Cherniack from the Broad Institute of MIT and Harvard; Tara Lichtenberg from Nationwide Children's Hospital, Columbus, Ohio; Carl Shelly from the University of Wisconsin; Christopher Benz from the Buck Institute for Research on Aging, Novato, Calif.; Gordon Mill from The MD Anderson Cancer Center; Peter Laird from the Van Andel Research Institute, Grand Rapids, MI; and Craig D. Shriver from the Walter Reed National Military Medical Center, Bethesda, MD.

To reach co-author Charles Perou, PhD, of the University of North Carolina Lineberger Comprehensive Cancer Center and professor of genetics, and pathology & laboratory medicine at the UNC School of Medicine, contact Laura Oleniacz, Science Communications Manager, UNC Lineberger Comprehensive Cancer Center, 919-445-4219, laura_oleniacz@med.unc.edu.

To reach co-author Hai Hu, PhD, vice president for research at the Chan Soon-Shiong Institute of Molecular Medicine at Windber contact Natalie Bombatch, Communications & Marketing Manager, Chan Soon-Shiong Institute of Molecular Medicine, Windber, PA, 814-467-3447, nbombatch@windbercare.org.

University of Chicago Medical Center

Related Breast Cancer Articles:

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.
Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.
Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.
More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.
Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.
Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.
Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.
Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.
Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.
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.
More Breast Cancer News and Breast Cancer Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab