This article is part of our February 2024 special issue. Download the full issue here.
Reference
Chen T, Kharazmi E, Fallah M. Race and ethnicity-adjusted age recommendation for initiating breast cancer screening. JAMA Netw Open. 2023;6(4):e238893.
Study Objective
To provide starting age recommendations for breast cancer screening based on race and ethnicity, using data based on race and ethnic disparities in breast cancer mortality as a guide
Key Takeaway
Unique screening guidelines should be considered for Black women due to their increased risk of developing breast cancer at an earlier age compared to other racial and ethnic groups.
Design
Nationwide population-based cross-sectional study
Participants
Investigators collected from US Mortality Data 415,277 breast cancer deaths involving women in the United States between 2011 and 2020. They collected race and ethnicity details from the National Vital Statistics System, which relies on death-certificate reporting by funeral directors. Data providers classified patients into 6 groups: Hispanic, non-Hispanic American Indian or Alaska Native, non-Hispanic Asian or Pacific Islander, non-Hispanic Black, non-Hispanic White, and unknown Hispanic origin. Investigators excluded patients of unknown Hispanic origin from the study (approximately 903 patients).
Study Parameters Assessed
Investigators calculated the risk-adapted starting age of breast cancer screening based on the 10-year cumulative risk of breast cancer–specific death by age, race, and ethnicity. The 10-year cumulative risk of breast cancer death was defined as the risk of dying due to breast cancer within the subsequent 10 years at each benchmark age.
Primary Outcome
The primary outcome was death due to invasive breast cancer regardless of histology and disease stage.
Key Findings
In this study, breast cancer–specific deaths totaled 415,277 female patients, including:
- 1,880 (0.5%) American Indian or Alaska Native
- 12,086 (2.9%) Asian or Pacific Islander
- 28,747 (6.9%) Hispanic
- 62,695 (15.1%) Black
- 309,869 (74.6%) White
Investigators observed differences in breast cancer–specific mortality based on race and ethnicity before age 50.
Between the ages of 40 to 49 years, breast cancer mortality rate per 100,000 person-years were as follows:
- Mean rate among total US females, 15 deaths
- Black females, 27 deaths
- White females, 15 deaths
- American Indian or Alaska Native, 11 deaths
- Asian or Pacific Islander, 11 deaths
- Hispanic females, 11 deaths
Investigators created different benchmarks based on age to calculate a risk threshold.
If the entire female population were screened at 50 years of age, the 10-year cumulative risk of breast cancer would be 0.039%. If this is an acceptable risk threshold (which is arbitrary), then to achieve an equivalent risk of 0.039% over a 10-year period, Black women would begin screening at 42 years of age. Additionally:
- Non-Hispanic White women would begin screening at 51 years.
- American Indian, Alaska Native, and Hispanic females would begin screening at 57 years.
- Asian and Pacific Islander females would begin screening at 61 years.
A screening age of 45 years for all women, regardless of race or ethnicity, gives a
- Black women, 38 years.
- Non-Hispanic White women, 46 years.
- Hispanic women, 49 years.
- Asian and Pacific Islander women, 50 years.
- American Indian or Alaska Native females, 51 years.
Lowering the screening age to 40 years for women would achieve an overall
- Black females would need to be screened at age 34 years,
- White females at age 41 years,
- Hispanic females at age 43 years, and
- American Indian or Alaska Native and Asian or Pacific Islander females at age 43 years.
Transparency
Supported by grants 2019YFE0198800 from the National Key Research Development Program of China and 2021R52020 from the Ten-Thousand Talents Plan of Zhejiang Province and by Start-up Funds for Recruited Talents in Zhejiang Cancer Hospital.
Practice Implications & Limitations
Current screening mammography guidelines do not consider racial differences in breast cancer survival.1
Breast cancer screening guidelines recommend starting ages for screening that range from 40 to 50 years and differ based on the issuing organization. The American Cancer Society recommends an initial mammography for women at average risk starting at age 45 and can begin as early as age 40.2 The American College of Obstetricians and Gynecologists recommends initial screening no later than age 50 for women at average risk but can be initiated beginning at age 40.3 And the United States Preventive Services Task Force recommends that screening begin at age 50 for women at an average risk for breast cancer.4 Although the current
screening guidelines have been associated with a reduction in breast cancer mortality, the disparity in risk reduction for Black women persists.
In general, Black females had an increased risk of dying due to early-onset breast cancer and so could be screened up to 8 years earlier than the recommended starting age of 50 years.
The authors report, “In general, Black females had an increased risk of dying due to early-onset breast cancer and so could be screened up to 8 years earlier than the recommended starting age of 50 years. Black females reached the risk threshold level at age 42 years, that were equivalent to White females at age 51 years, American Indian or Alaska Native and Hispanic females at age 57 years, and Asian or Pacific Islander females 11 years later, at age 61 years. Race and ethnicity–adapted starting ages for Black females were consistently lower to achieve similar risk of breast cancer mortality, specifically they were 6 years earlier for mass screening at age 40 years and 7 years earlier for mass screening at age 45 years.”5
In a study published in the Annals of Internal Medicine in 2021, the Cancer Intervention and Surveillance Modeling Network found that biennial screening from ages 40 to 74 years could be associated with a 57% decrease in the breast cancer mortality gap between Black and White women.1
From the study under review here, the authors write, “BC mortality depends on many factors, such as differences in distribution of breast size and density, quality of screening tests, host tumor microenvironment, treatment access and quality, competing mortality, distribution of phenotype prevalence of BC, tumor grading and staging at diagnosis, initiation of breast cancer treatment, type of treatment received, barriers to health care access, poverty level, biological and genetic differences in tumors, and prevalence of risk factors associated with the periods during and after cancer treatment, and other factors. But these factors cannot justify the higher mortality of early-onset breast cancer in Black females younger than the recommended age of mass screening.”5
The study findings justify the need to adjust the current 1-size-fits-all screening guidelines for breast cancer to improve survival and reduce mortality risk.
