When it comes to breast cancer, Black women experience earlier onset, more serious disease, and higher mortality versus White women, but a race-specific screening approach could mitigate these inequities, according to a modeling study.
In the simulation model of 100 million Black and White women in the U.S., kick-starting biennial screening mammography in the former at age 40 cut 57% of the racial disparity in expected mortality compared with the latter, reported Christina Hunter Chapman, MD, MS, of the University of Michigan in Ann Arbor, and co-authors.
Under current U.S. Preventive Services Task Force (USPSTF) guidelines, if Black and White women were screened biennially, from ages 50 to 74, the excess death rate would come in at 3.29 among Black women (17.62 vs 14.33 deaths/1,000 persons for Black vs White women), they wrote in the Annals of Internal Medicine.
However, Chapman’s group noted that USPSTF guidelines do not explicitly consider racial differences in breast cancer epidemiology, treatment, and survival, and “race-neutral screening guidelines can do harm if they yield unequal outcomes and are applied instead of more equitable alternatives that retain acceptable tradeoffs.”
The medical community “must learn how to be race conscious without being racist,” advised David S. Jones, MD, PhD, of Harvard University in Cambridge, Massachusetts, in an editorial accompanying the study.
Yet he also cautioned that medicine’s “reflexive use of race diverts attention from other factors that are relevant—possibly more relevant than genetics and race. Race is a powerful force in American society, but so is class.”
Jones added that he has yet to come across a clinical tool that incorporates “racism and socioeconomic status… If we think human differences are important and should inform medical practice, then we need to invest the effort required to map and understand those differences.”
For their analysis, the study authors used Cancer Intervention and Surveillance Modeling Network (CISNET) models to compare the tradeoffs of screening strategies for Black women versus White women under current task force guidelines.
The CISNET Model GE was adapted to a 1980 U.S. birth cohort of Black and White women to simulate screening outcomes using race-specific inputs for subtype distribution; breast density; mammography performance; age-, stage-, and subtype-specific treatment effects; and non-breast cancer mortality.
“In brief, model GE is a parallel-universe population simulation model that begins with estimates of breast cancer incidence and survival trends, specific to molecular subtype (based on estrogen receptor [ER] and human epidermal growth factor receptor 2 [HER2] status), in the absence of screening or adjuvant treatment,” Chapman’s group explained.
Outcomes included benefits in the form of life-years gained (LYG), breast cancer deaths averted, and mortality reduction; harms (mammographies, false positives, and overdiagnoses); and benefit-harm ratios (tradeoffs) by race.
Results from simulated biennial screening of White women followed by optimal systemic therapy served as the benchmark for acceptable benefit–harm ratios, the authors noted.
They evaluated nine mammography screening strategies, varied by starting age and interval, to identify equitable screening strategies for Black women that yielded benefit-harm tradeoffs similar to those of White women screened according to USPSTF guidelines.
The researchers modeled 100 million life histories from birth to death in the absence of screening and treatment. This model was then repeated among Black women with screening and treatment effects for each of nine strategies.
They reported that the strategy that yielded the LYG/M ratio closest to the benchmark for White women was biennial screening from ages 40 to 74 (15 vs benchmark: 14.5 LYG/M).
Chapman and co-authors found that, with biennial screening in Black women starting at age 40, deaths would decrease by 1.88/1,000 women (from 17.62 to 15.74), removing 57% of the racial disparity in mortality expected under current guideline screening (1.88 of 3.29 excess deaths).
“Our results suggest that, in self-identified Black women, initiation of earlier screening than is presently recommended for the overall U.S. population by the USPSTF or the American Cancer Society can reduce mortality disparities and maintain acceptable benefit-harm tradeoffs,” they wrote.
Study limitations included the use of a single model, and that patterns of mammography screening may vary by age and race, thereby affecting screening outcomes. Also, associations between race and health or societal outcomes are often rooted in racism as opposed to biology, and “race and racism (whether structural, interpersonal, or internalized) are complex constructs.”
Previous research would certainly support that statement from Chapman’s group. A 2019 study in Social Science & Medicine looked at self-reported barriers to mammography screening in racial/ethnic minority women and found that cultural/immigration-related barriers seemed to be the only barrier type that was unique to racial/ethnic minority women, leading the authors of that study to suggest that “designing studies of barriers around race and ethnicity is not always appropriate, and other demographic factors are sometimes a more important focus.”
A 2020 study in LGBT Health reported that “[s]exual orientation identity disparities in receiving a mammogram in the past year differed in relationship to race/ethnicity among White, Black, and Latina U.S. women,” although the differences did not reach statistical significant because of a small patient population.
In a 2021 study in Policy, Politics, & Nursing Practice, Mollie E. Aleshire, DNP, MSN, of the University of Louisville in Kentucky, and co-authors pointed out that “health care reform through the ACA [Affordable Care ACt] played a pivotal role in reducing financial impediments to accessing mammography… yet, barriers to mammography persist. Despite interventions such as mobile mammography vans that bring physical access to communities, Black women continue to lag behind in mammography screening.”
A 2021 systematic review in Public Health from the U.K. found three main barriers to screening for Black, Asian, and ethnic minority women—access, cultural, and knowledge—and emphasized that addressing the last hurdle may offer the best results for boosting screening uptake.
However, in an October 2021 AllHealthGo YouTube Town Hall, Haywood Brown, MD, of University of South Florida Health in Tampa, noted that for U.S. women of color, access may be the bigger problem. “I have to remind people that we live in a very rural country for the most part. The reality is that 50% of all [U.S.] counties don’t have a practicing OB/GYN, so access to care is a real issue,” he said, adding that even if a woman has access to screening services, she may not be able to afford the cost of the exam, particularly if she is uninsured.
Jane Mendez, MD, of the Miami Cancer Institute, stressed in the Town Hall that providing access, such as with mobile mammography, is important, but that people in the community need to be recruited to encourage women to use mobile services regardless of their insurance status.
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For Black women, initiating biennial screening at age 40 reduced breast cancer mortality disparities and yielded benefit–harm ratios that were similar to tradeoffs for White women screened biennially from ages 50 to 74.
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These findings suggest that, in self-identified Black women, initiation of earlier screening than is presently recommended for the overall U.S. population by the USPSTF or the American Cancer Society can reduce mortality disparities and maintain acceptable benefit-harm tradeoffs.
Shalmali Pal, Contributing Writer, BreakingMED™
The study was funded by the National Cancer Institute (NCI) and NCI/Breast Cancer Surveillance Consortium.
Hunter Chapman reported support from NCI. Co-authors reported support from, and or relationships with, NCI, TIME’S UP Healthcare, American Society of Clinical Oncology, American Society of Radiation Oncology (ASTRO), Sherinian and Hasso, and Dressman Benzinger LaVelle.
Jones reported no relationships relevant to the contents of this paper to disclose.
Cat ID: 115
Topic ID: 78,115,730,115,22,191,691,142,192,925,481,96
