About 5% to 10% of breast cancers are thought to be hereditary, caused by abnormal genes passed from parent to child.
Genes are particles in cells, contained in chromosomes, and made of DNA (deoxyribonucleic acid). DNA contains the instructions for building proteins. And proteins control the structure and function of all the cells that make up your body. You can think of your genes as an instruction manual for cell growth and function. Abnormalities in DNA are like typographical errors. They may provide the wrong set of instructions, leading to faulty cell growth or function.
The Jewels in Our Genes study has discovered DNA abnormalities shared by black family members who have been diagnosed with breast cancer. These abnormalities could lead to the discovery of gene mutations linked to breast cancer that are unique to blacks.
The research was published in the February 2015 issue of Cancer Epidemiology, Biomarkers & Prevention. Read the abstract of “Putative Linkage Signals Identified for Breast Cancer in African American Families.”
A companion article published in November 2014 of the same journal talks about how people were recruited for the Jewels in Our Genes study. Read the abstract of “Abstract B12: Recruitment of African American breast cancer pedigrees for The Jewels in Our Genes Study: Recruitment outcomes and sample characteristics.”
Black women are more likely than white women to be diagnosed with breast cancer when they’re younger than 40. Black women also are much more likely than white women to be diagnosed with triple-negative breast cancer.
Triple-negative breast cancer is:
Triple-negative breast cancers can be more aggressive, harder to treat, and more likely to come back (recur) than cancers that are hormone-receptor-positive or HER2-positive. Triple-negative breast cancers don’t usually respond to hormonal therapy medicines or targeted therapy medicines for HER2-positive disease.
Black women can carry abnormal BRCA1 or BRCA2 genes, which are linked to a higher risk of breast cancer. Still, researchers suspect that there may be more, undiscovered abnormal genes that are linked to breast cancer in black women.
In the Jewels in Our Genes study, researchers looked at the DNA of 106 black families who didn’t have a known abnormal BRCA1 or BRCA2 gene. The participants included 179 women who had been diagnosed with breast cancer and 76 of their sisters who had never been diagnosed.
The researchers found three abnormal DNA regions. One of the abnormal regions was near the BRCA1 gene on chromosome 17.
“The discovery of these regions supports our hypothesis that there are still undiscovered breast cancer genes that may be unique to African Americans,” said Heather Ochs-Balcom, Ph.D., a genetic epidemiologist at the University of Buffalo who led the study. “We can now focus on these specific chromosomes to learn if they house genetic mutations linked to breast cancer.”
The research is similar to the groundbreaking work that led to the discovery of abnormal BRCA1 and BRCA2 genes being linked to a much higher risk of breast cancer.
The Jewels in Our Genes study was spurred by Veronica Meadows-Ray of Buffalo, NY. A breast cancer survivor, she asked if a study could be done to look into why her mother, aunt, and several cousins were diagnosed with breast cancer, even though they had tested negative for an abnormal BRCA1 or BRCA2 gene. Ms. Meadows-Ray suspected that the cancer in her family was hereditary and caused by genetic mutations unique to blacks.
No one can change their genetics. But if you’re a black woman, there are steps you can take to keep your risk of breast cancer as low as it can be.
You may want to talk to your doctor about a new breast cancer risk prediction model for black women that is more accurate than traditional models.
There are also lifestyle choices that you may want to make, including:
- maintaining a healthy weight
- exercising every day
- limiting or avoiding alcohol
- eating a healthy diet that’s low in processed foods, sugar, and trans fats
- not smoking
To learn more about breast cancer risk and other options to keep your risk as low as it can be, visit the Breastcancer.org Lower Your Risk section.