This article was originally published on February 4, 2023 and updated in 2024 and 2025.

We know the data.

Black Breasties face different outcomes following cancer diagnoses than their white counterparts, with increased rates of more aggressive subtypes of breast cancer, like triple negative and inflammatory, and higher rates of mortality even as survival rates increase overall.

This World Cancer Day, The Peak is taking a dive into the research that examines why these disparities exist and what’s being done to improve outcomes for Black Breasties.

Examining the epidemiology 

Research on the causes of breast cancer in Black patients falls behind that on white patients. 

To address the knowledge gap, the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium pulled together data from four studies with the goal of understanding “the impact of genetic and lifestyle factors on the risk of breast cancer subtypes in African American women.”

The Consortium reviewed data from more than 20,000 Black people included in the four parent studies, including 5,700 with a breast cancer diagnosis, allowing them to “provide the largest dataset to date on the frequency of breast cancer subtypes” in Black patients. 

The Consortium has also enabled researchers to understand whether previous research around epidemiology of breast cancer applies equally to Black and white folks. 

For example, one such study notes that the inverse association between dietary vitamin A and breast cancer observed in white women is consistent in Black women, while another found that increased alcohol intake remains a risk factor regardless of racial background. 

Deep dive into ovarian cancer survivorship

In a similar vein, the African-American Cancer Epidemiology Study (AACES) aims to better understand the causes and prognosis of ovarian cancer in Black patients. 

The second phase of the study, which began in 2020, is the first of its kind to focus on Black epithelial ovarian cancer survivors, the most common type of ovarian cancer. 

In doing so, researchers hope to “[understand] factors that influence mortality to better understand why Black women experience worse survival after a diagnosis,” which can then be used to develop “strategies to reduce this racial disparity.”

Disparities in rates of local recurrence

In an effort to better understand the differences in outcomes by race and ethnicity, researchers from Memorial Sloan Kettering Cancer Center retrospectively examined just over 4,200 cases of patients with non-invasive breast cancer treated between 1978 and 2016.

They found that Black patients were more likely, when compared to their white, Asian or Latine counterparts, to have their cancer return within 10 years after examining the local recurrence rate among those who had breast-conserving surgery, such as a lumpectomy, and radiation.

They say this was seen despite the facts that the same number of Black and white patients had been living with their diagnosis since 1998 or earlier, that more Black patients had received endocrine therapy, and that the rates of low, intermediate, and high grade disease were the same among the racial groups. They also did not find an association with family history or grade of disease, among other factors. 

So how can this information be used to improve outcomes for Black patients? The researchers suggest that care providers should keep this in mind when considering additional post-surgical—also known as adjuvant—treatments. 

Identifying common gene variants for better screening

Why are some Black patients more likely to develop aggressive breast cancers, like triple negative?

Researchers believe they have identified a genetic clue in what is thought to be the largest genome-wide association study (GWAS) among this population to date. 

Using data from the African Ancestry Breast Cancer Genetic Consortium, which gathered data from more than 40,000 females of African descent across 26 studies, researchers found 12 genetic loci— or locations within a genome—associated with breast cancer, including three related to triple negative breast cancer. 

From there, they were able to find that people who have two genetic copies of risk variants in these three locations are 4.2 times more likely to develop triple-negative breast cancer than those without. 

This information, the researchers explain, can be used to improve screening, through the creation of polygenic risk scores (PRS) “for breast cancer risk in females of African descent.” A PRS is a calculation that can estimate someone’s lifetime risk of a disease. However, these calculations are limited by the data used to create them. Because of the information gathered by researchers in this study, they successfully developed a PRS that is more accurate for people of African descent.  

Social factors influencing genetic testing

One paper published using AACES data, aimed to explore the social and psychological factors that could influence a Black patient’s decision to seek genetic testing. 

Researchers say that of 270 Black ovarian cancer patients, one-third reported having had genetic testing. They found that those “with higher incomes had more than double the odds of being tested than those with the lowest income” and that experiences of employment discrimination also impacted rates of genetic testing. 

While these results are in line with other studies of Black patients, the researchers say that this information provides the “foundational evidence supporting the need for interventions to improve the uptake of genetic testing among [Black patients] by reducing cost barriers and providing credible assurances that genetic results will be kept private and not affect social factors such as employability.”

Differences in disclosure of genetic testing results

What happens once a patient has decided to seek genetic testing?

With past research related to the disclosure of genetic testing results focusing largely on white people, researchers hoped to address this gap in knowledge by zeroing-in on to whom Black people disclose their results, positive or otherwise. 

What they found was that Black people who test positive for a BRCA 1 or 2 genetic variant “were significantly less likely to disclose results to their daughters” within a year of receiving their results. 

This, researchers say, “may have direct health implications to these family members” and suggest that health care providers “tailor discussions of disclosure … highlighting the importance of communicating positive results to certain family members.” 

Identifying immune responses

In an effort to understand why Black patients often face more aggressive breast cancer subtypes, a study published in the Journal of the National Cancer Institute examined the breast tumor microenvironment–or the blood vessels, immune cells, molecules, and normal cells that surround a tumor–focusing on their immune response. 

What they found was “marked and consistent differences in tumor immune responses between Black and White patients,” which, they say, “indicate an immunobiological basis for [Black patients’] more aggressive disease.” 

This increased understanding of the breast tumor microenvironment in some Black patients “may have clinical implications,” such as immune checkpoint inhibitors, a type of immunotherapy. 

However, the study points out that clinical trials on immune checkpoint inhibitors currently have limited race-specific data. As such, researchers say increasing the “recruitment of racial and ethnic minorities into clinical trials is warranted to close the gaps in cancer disparities and to ensure that all groups of patients will benefit from advances in cancer therapeutics.”

Social drivers of stress responses

How do lived experiences and social stressors influence breast cancer in Black patients?

A study published in Nature examined cortisol levels in Black patients with breast cancer to understand how stress responses relate to social and clinical factors. Among 72 participants, findings revealed that those with hypertension were 6.84 times more likely to have high cortisol levels, and each additional negative life event increased the odds of high cortisol by 1.42 times.

The study builds on emerging research that links chronic stress exposure—especially socioeconomic and racial stressors—to dysregulated hypothalamic-pituitary-adrenal (HPA) axis functioning. Given that cortisol dysregulation has been implicated in cancer progression, these findings underscore the need for a more holistic approach to cancer care. Addressing social determinants of health, such as economic strain and social isolation, may be just as critical as clinical interventions in improving outcomes for Black breast cancer patients.

The results also align with broader research on racial disparities in health, which shows that Black individuals experience a higher burden of chronic stress due to systemic inequities, which may contribute to worse health outcomes.