A new study found that Black women are more likely to die from breast cancer than white women, regardless of the tumor subtype

Study: Black Women More Likely to Die from Breast Cancer—How Can the US Close the Gap?

A new study found that Black women are more likely to die from breast cancer than white women, regardless of the tumor subtype

• A new study found that Black women are more likely to die from breast cancer than white women across all subtypes of the disease.
• Previous research has established the higher mortality rate for Black women, but the new study points to systemic disparities, not a difference in breast cancer type, to explain the gap.
• Experts say it’s up to healthcare systems to address barriers to treatment and better track patients to ensure no one is left behind.

Even though Black and white women are diagnosed with breast cancer at similar rates, Black women are around 40% more likely to die from the disease. Now, a new study has found that this is true across all types of breast cancer. 

According to the research, published in September in the Journal of Clinical Oncology, this outcome is at least partially due to factors other than biology, including socioeconomic inequality, delays in diagnosis, and systemic racism.

“Black women are more likely to die of breast cancer no matter the subtype,” Jasmine Miller-Kleinhenz, PhD, assistant professor of population health at the University of Mississippi Medical Center, told Health. “This is important because it highlights that these health disparities are not just a matter of tumor biology, but are determined by social and structural drivers of health.”

Here’s what experts had to say about the new study and how the U.S. can address breast cancer disparities between Black and white women.

Breast Cancer Subtypes and Racial Disparities

The fact that Black women die from breast cancer at higher rates than white women is well-established. However, not all cases of breast cancer are the same. The aim of the new research was to determine whether disparities in mortality rate exist across all subtypes of breast cancer.

There are multiple types of breast cancer, and all of them have different risk factors, treatments, and prognosis. These subtypes are based on different hormones, as well as a protein called human epidermal growth receptor 2 (HER2).

When a tumor doesn’t have progesterone or estrogen receptors and doesn’t make much HER2 protein, it’s considered “triple-negative.” This is the most aggressive type of breast cancer and has few treatment options.

Meanwhile, tumors that express estrogen and/or progesterone (called hormone receptor-positive) have a better prognosis. If cancer cells make more HER2 protein, they’re called HER2-positive—these tumors spread more quickly but also better respond to treatment as compared to HER2-negative tumors.

And there are documented racial differences among these subtypes. As compared to white women, Black women have a higher incidence of triple-negative tumors and a lower incidence of easier-to-treat hormone receptor-positive/HER2-negative tumors.

Greater Mortality Gaps Among Certain Types of Breast Cancer

The higher prevalence of aggressive breast cancer tumors in Black women contributes to the racial disparity in mortality, but it doesn’t fully explain it, the new research found.

For the study, the researchers analyzed 18 studies published between 2009 and 2022 that included 34,262 Black patients and 182,466 White patients with stage I to IV breast cancer.

They found that, as compared to white women, Black women had a 50% higher risk of death from hormone receptor-positive/HER2-negative tumors and a 34% higher mortality risk from hormone receptor-positive positive/HER2-positive tumors. For the more dangerous hormone receptor-negative tumors, Black women had a 20% and 17% higher mortality rate from HER2-positive and HER2-negative tumors, respectively.

Essentially, “Black women are dying at a higher rate of breast cancer, whether the tumor is considered prognostically favorable or not,” Miller-Kleinhenz explained.

These results suggest that there is something beyond biology driving these disparities, said Erica Warner, ScD, MPH, a cancer epidemiologist at Massachusetts General Hospital and senior author of the study.

“There was some thought that the higher prevalence of triple-negative tumors in Black women was a significant contributor to disparities,” Warner told Health. “Tumor subtypes matter, but can’t explain the differences in survival because, among Black and white women with the same tumor subtype, we still found that Black women were more likely to die.”

Hormone receptor-positive tumors are easier to detect with mammography and have more treatment options, Warner explained. However, this also presents “more opportunity for gaps in care,” she said, which could explain the greater racial morality disparities seen in the study results.

Despite the study’s large sample size, there are a few limitations. For one, the study had relatively low numbers of people in some of the subtype analyses, Warner said, which could’ve impacted precision. Also, because the researchers didn’t have individual data for all of the study participants, they weren’t able to determine how factors such as treatment or experiences of racism could’ve affected the results, she added.

Why Do These Breast Cancer Disparities Exist?

Previous research has shown that Black women tend to be diagnosed with breast cancer at a younger age than White women. Plus, while breast cancer rates have remained stable among white women, they have increased by 0.4% per year among Black women since 1975.

And these disparities aren’t unique to Black women. American Indian/Alaska Native (AIAN) women have higher breast cancer mortality rates than white women, despite lower incidence. And Black, Hispanic, and AIAN women are less likely to be diagnosed with localized-stage breast cancer (meaning it’s easier to treat) as compared to Asian/Pacific Islander and white women.

So why is this the case?

“Access to care, socioeconomic barriers, and cultural challenges in navigating the healthcare system all contribute to these disparities,” Corey Speers, MD, PhD, a radiation oncologist and co-director of the breast cancer program at the University Hospitals Cleveland Medical Center, told Health. “Though the exact drivers may differ across groups, the common theme is a lack of equitable access to early diagnosis and cutting-edge treatment.”

This can manifest in a number of ways. For one, “Black women may face greater health insurance inequities than other populations,” Tingting Tan, MD, PhD, a medical oncologist and hematologist at City of Hope Newport Beach, told Health.

Women of color may also have less access to high-quality healthcare institutions, making it harder for them to receive mammography or other preventative screening, as well as quality treatment after they’re diagnosed, Speer and Tan explained.

For example, lower-income patients may have a harder time arranging childcare, taking time off of work, and getting transportation to a treatment facility, said Tan. Plus, Speer added, mistrust of medical institutions may also decrease the likelihood that Black women get high-quality treatment or follow-up care once they’ve been diagnosed with breast cancer.

These social determinants of health are coupled with genetic or biological factors that drive disparities in cancer mortality, too. Black women are twice as likely to develop triple-negative breast cancer as compared to white women and are also more likely to have other conditions that increase breast cancer risk, including diabetes, obesity, and heart disease, Tan said.

“It’s not just biology—at times, it is the system itself is contributing to the disparities in mortality,” Speer said.

Addressing Disparities and Reducing Breast Cancer Mortality

To ultimately close these gaps in breast cancer mortality, experts say there are a number of systemic changes that need to happen.

“This includes improving access to timely, high-quality care, and ensuring that all women—regardless of race or socioeconomic status—have access to the same advanced treatments and clinical trials,” Speers said.

Data consistently show that Black women have mammography screening rates that are the same or better than white women in the U.S., Warner pointed out. So, she said, “this suggests that to improve early detection, we need to make sure that women with abnormal findings receive timely diagnostic care and treatment.”

To that end, healthcare systems should track their breast cancer patients, and use demographic factors to identify any gaps or treatment steps where some people are being left behind, Warner said.

There’s also a need for more studies that can investigate how various structural, social, and environmental drivers of health are impacting communities, Miller-Kleinhenz said.

“This will require developing cohorts that have more Black women represented and that have data that will allow us to study these important questions so that we can close this gap and achieve the ultimate goal of health equity,” she said.

Healthcare practitioners also play a role.

“As breast radiologists, we have to do our due diligence in raising awareness about healthcare disparities that affect the lives of our patients,” Georgia Spear, MD, division chief of breast imaging at Endeavor Health, told Health. “We also need to take action to ensure equitable access to health care so all women have the lifesaving care they need.”

This story originally appeared on: Health News - Author:Elizabeth Yuko, PhD