Why do Black women die more often from breast cancer?
- A new study led by Sanford Burnham Prebys researchers investigated why Black women with breast cancer have a higher mortality rate than white women with breast cancer.
- The researchers discovered that the processes for repairing damaged DNA within cells differ at the molecular level.
- The study's findings suggest that doctors may need to modify treatment plans for Black women with breast cancer in order to improve their chances of survival.
Less favourable outcomes in Black women with breast cancer are due, in part, to racial disparities in healthcare.
According to the authors of one paper Trusted Source, "despite medical advances in early detection, diagnosis, and screening, many Black women are less likely to receive adequate treatment than white women."
A new study published in Therapeutic Advances in Medical Oncology suggests that biological factors may contribute to this disparity.
The study looked at genetic differences between black and white women and discovered that there is a difference in the cellular response to damaged DNA.
According to 2018 demographic data, the rate of breast cancer occurrence among Black women and white women was comparable.
The rate of new breast cancer cases among Black women was 121.2 per 100,000 women. In comparison, the rate among white women was 127.5 per 100,000.
Although there was only a 5% difference in the number of cases of breast cancer between Black and white women, the difference in mortality rate was much greater.
According to 2018 data, white women had a mortality rate of 19.2 per 100,000 cases of breast cancer, while black women had a mortality rate of 26.8 per 100,000 cases. This equates to a roughly 40% higher rate in Black women than in white women.
Dr. Lola Fayanju discusses breast cancer in a podcast with BreastCancer.orgTrusted Source, pointing out the mortality rate difference. Dr. Fayanju is the surgical director at Philadelphia's Rena Rowan Breast Center.
"In the United States, white women are the most likely of any racial or ethnic group to be diagnosed with breast cancer," Dr.Fayanju says. "However, there are significant disparities in who is most likely to die from breast cancer, which is generally a highly curable disease."
"For early stage breast cancer, survival rates are often greater than 90%," Dr. Fayanju explains. "However, among Women of Color, particularly African American women, we see much higher mortality rates, which is partly due to people presenting with later stage disease."
Although the researchers behind the new study acknowledge that this disparity contributes to higher mortality rates among Black women, their findings suggest that a molecular difference also plays a role.
"Society has internalised the narrative that lifestyle factors are to blame for racial differences in health outcomes," says lead author Dr. Svasti Haricharan, "so most scientists don't look at molecule-level differences between people."
Dr. Haricharan is an assistant professor in the Sanford Burnham Prebys Medical Discovery Institute's Aging, Cancer, and Immuno-oncology Program in La Jolla, California.
The researchers compared cancerous and normal breast tissue from Black and white women who were both oestrogen receptor-positive (ER-positive). They discovered that eight DNA damage response and repair (DDR) genes in Black women functioned differently in normal and cancerous tissue.
Some of the DDR genes that were dysregulated inhibited the repair response.
"What we're seeing here is a tangible molecular difference in how these cells repair damaged DNA, which affects how cells grow and reproduce in tumours," says Dr. Haricharan.
"This is something we can do right away because helping these women is less about finding a new drug and more about changing the timing for treatments we already have," Dr. Haricharan says.
In the later stages of treatment for ER-positive breast cancer, doctors use cyclin-dependent kinase inhibitors, according to the researchers. However, they may be able to introduce this earlier in Black women with breast cancer to improve their prognosis.
"This is critical because if normal tissue differs at the molecular level based on race or ethnicity, then everything we know about how each of us responds to cancer treatment will differ."– Dr. Haricharan,
Dr. Haricharan spoke with Medical News Today about the study and the team's future plans. She outlined some possible next steps:
"Creating a large molecular database that represents breast cancer in Black women — something that is currently lacking — in order to fully understand the molecular drivers that are unique to breast cancer cells in Black women."
"Because black women are severely underrepresented in virtually all datasets of patient tumours, many previous findings about breast cancer only accurately reflect what's happening to white women," Dr. Haricharan explained. "We hope that our findings will highlight the importance of studying cancer in different racial and ethnic groups in order to improve outcomes for historically marginalized patients."
She would also like to use experimental model systems to test "the molecular relationships we observe between the DNA repair signature occurring in ER-positive breast cancer samples from Black women and response to cell cycle inhibitors."
Palbociclib (Ibrance) is a cell cycle inhibitor that, according to Dr. Haricharan, "is already [approved by the Food and Drug Administration FDA] for late stage ER-positive breast cancer but may be beneficial to provide to Black women with ER-positive breast cancer early in their disease timeline."
Securing funding is another critical step, which Dr.Haricharan identified as the "largest hurdle to doing this research."
Dr. Haricharan is said to have a "provisional patent for using DNA repair genes as a biomarker for patient outcome," according to the authors.
Dr. Stephen J. Freedland is also a consultant for Pfizer, Janssen, AstraZeneca, Merck, and Clovis.
According to the authors of one paper Trusted Source, "despite medical advances in early detection, diagnosis, and screening, many Black women are less likely to receive adequate treatment than white women."
A new study published in Therapeutic Advances in Medical Oncology suggests that biological factors may contribute to this disparity.
The study looked at genetic differences between black and white women and discovered that there is a difference in the cellular response to damaged DNA.
Breast cancer statistics
According to the Centre for Disease Control and Prevention (CDC)Trusted Source, approximately 255,000 women in the United States develop breast cancer each year, with approximately 42,000 women dying. Breast cancer is the second leading cause of cancer death in women overall.According to 2018 demographic data, the rate of breast cancer occurrence among Black women and white women was comparable.
The rate of new breast cancer cases among Black women was 121.2 per 100,000 women. In comparison, the rate among white women was 127.5 per 100,000.
Although there was only a 5% difference in the number of cases of breast cancer between Black and white women, the difference in mortality rate was much greater.
According to 2018 data, white women had a mortality rate of 19.2 per 100,000 cases of breast cancer, while black women had a mortality rate of 26.8 per 100,000 cases. This equates to a roughly 40% higher rate in Black women than in white women.
Dr. Lola Fayanju discusses breast cancer in a podcast with BreastCancer.orgTrusted Source, pointing out the mortality rate difference. Dr. Fayanju is the surgical director at Philadelphia's Rena Rowan Breast Center.
"In the United States, white women are the most likely of any racial or ethnic group to be diagnosed with breast cancer," Dr.Fayanju says. "However, there are significant disparities in who is most likely to die from breast cancer, which is generally a highly curable disease."
"For early stage breast cancer, survival rates are often greater than 90%," Dr. Fayanju explains. "However, among Women of Color, particularly African American women, we see much higher mortality rates, which is partly due to people presenting with later stage disease."
Breast cancer molecular study
According to some studies, socioeconomic status TrustedSource is a major cause of the increased mortality rate. It contributes to Black women not having equal access to healthcare, causing problems with preventive care, cancer detection, and treatment.Although the researchers behind the new study acknowledge that this disparity contributes to higher mortality rates among Black women, their findings suggest that a molecular difference also plays a role.
"Society has internalised the narrative that lifestyle factors are to blame for racial differences in health outcomes," says lead author Dr. Svasti Haricharan, "so most scientists don't look at molecule-level differences between people."
Dr. Haricharan is an assistant professor in the Sanford Burnham Prebys Medical Discovery Institute's Aging, Cancer, and Immuno-oncology Program in La Jolla, California.
The researchers compared cancerous and normal breast tissue from Black and white women who were both oestrogen receptor-positive (ER-positive). They discovered that eight DNA damage response and repair (DDR) genes in Black women functioned differently in normal and cancerous tissue.
Some of the DDR genes that were dysregulated inhibited the repair response.
"What we're seeing here is a tangible molecular difference in how these cells repair damaged DNA, which affects how cells grow and reproduce in tumours," says Dr. Haricharan.
Study implications
According to the study's findings, doctors may need to modify treatment plans for Black women with breast cancer."This is something we can do right away because helping these women is less about finding a new drug and more about changing the timing for treatments we already have," Dr. Haricharan says.
In the later stages of treatment for ER-positive breast cancer, doctors use cyclin-dependent kinase inhibitors, according to the researchers. However, they may be able to introduce this earlier in Black women with breast cancer to improve their prognosis.
"This is critical because if normal tissue differs at the molecular level based on race or ethnicity, then everything we know about how each of us responds to cancer treatment will differ."– Dr. Haricharan,
Dr. Haricharan spoke with Medical News Today about the study and the team's future plans. She outlined some possible next steps:
"Creating a large molecular database that represents breast cancer in Black women — something that is currently lacking — in order to fully understand the molecular drivers that are unique to breast cancer cells in Black women."
"Because black women are severely underrepresented in virtually all datasets of patient tumours, many previous findings about breast cancer only accurately reflect what's happening to white women," Dr. Haricharan explained. "We hope that our findings will highlight the importance of studying cancer in different racial and ethnic groups in order to improve outcomes for historically marginalized patients."
She would also like to use experimental model systems to test "the molecular relationships we observe between the DNA repair signature occurring in ER-positive breast cancer samples from Black women and response to cell cycle inhibitors."
Palbociclib (Ibrance) is a cell cycle inhibitor that, according to Dr. Haricharan, "is already [approved by the Food and Drug Administration FDA] for late stage ER-positive breast cancer but may be beneficial to provide to Black women with ER-positive breast cancer early in their disease timeline."
Securing funding is another critical step, which Dr.Haricharan identified as the "largest hurdle to doing this research."
Dr. Haricharan is said to have a "provisional patent for using DNA repair genes as a biomarker for patient outcome," according to the authors.
Dr. Stephen J. Freedland is also a consultant for Pfizer, Janssen, AstraZeneca, Merck, and Clovis.