Study: At what age should breast cancer screening begin?

reference

Chen T, Kharazmi E, Fallah M. Race and ethnicity-adjusted age recommendation for initiation of breast cancer screening.JAMA Network Open. 2023;6(4):e238893.

Study objective

Provide recommendations on the age of initiation of breast cancer screening based on race and ethnicity using data based on racial and ethnic disparities in breast cancer mortality as a guide

Key to take away

Special screening guidelines should be considered for black women because the risk of developing breast cancer at an earlier age is higher compared to other racial and ethnic groups.

design

Nationwide population-based cross-sectional study

Participant

Investigators collected 415,277 breast cancer deaths among women in the United States between 2011 and 2020 using U.S. mortality data. They collected race and ethnicity information from the National Vital Statistics System, which relies on death certificate reporting by funeral homes. 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. Researchers excluded patients of unknown Hispanic origin from the study (approximately 903 patients).

Evaluated study parameters

Researchers calculated the risk-adjusted start age for 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 dying from breast cancer was defined as the risk of dying from breast cancer within the following 10 years at each reference age.

Primary outcome

The primary endpoint was death from invasive breast cancer, regardless of histology and stage of disease.

Key findings

In this study, a total of 415,277 patients died from breast cancer-related deaths, including:

• 1.880 (0,5 %) Indianer oder Ureinwohner Alaskas
• 12.086 (2,9 %) asiatische oder pazifische Inselbewohner
• 28.747 (6,9 %) Hispanoamerikaner
• 62.695 (15,1 %) Schwarz
• 309.869 (74,6 %) Weiß

Researchers observed differences in breast cancer-specific mortality based on race and ethnicity before age 50.

Between ages 40 and 49, the breast cancer mortality rate per 100,000 person-years was as follows:

• Durchschnittliche Sterberate unter allen US-amerikanischen Frauen: 15 Todesfälle
• Schwarze Frauen, 27 Todesfälle
• Weiße Frauen, 15 Todesfälle
• Indianer oder Ureinwohner Alaskas, 11 Todesfälle
• Asiatischer oder pazifischer Inselbewohner, 11 Todesfälle
• Hispanische Frauen, 11 Todesfälle

Investigators created different benchmarks based on age to calculate a risk threshold.

If the entire female population were screened at age 50, the 10-year cumulative risk of breast cancer would be 0.039%. If this is an acceptable risk threshold (which is arbitrary), black women would need to begin screening at age 42 to achieve an equivalent risk of 0.039% over 10 years. Additionally:

• Nicht-hispanische weiße Frauen würden mit 51 Jahren mit dem Screening beginnen.
• Amerikanische Indianer, Alaska-Ureinwohner und hispanische Frauen würden mit 57 Jahren mit dem Screening beginnen.
• Frauen aus asiatischen und pazifischen Inseln beginnen mit dem Screening im Alter von 61 Jahren.

A screening age of 45 for all women, regardless of race or ethnicity, yields one

The mean cumulative 10-year risk of dying from breast cancer is 0.235%. The screening age to reach this risk threshold percentage of 0.235% would be:

• Schwarze Frauen, 38 Jahre.
• Nicht-hispanische weiße Frauen, 46 Jahre.
• Hispanische Frauen, 49 Jahre.
• Asiatische und pazifische Inselbewohnerinnen, 50 Jahre.
• Amerikanische Indianerinnen oder Alaska-Ureinwohnerinnen, 51 Jahre.

Lowering the retirement age for women to 40 would bring about an overall improvement

The mean cumulative 10-year risk of dying from breast cancer is 0.154%. To achieve this risk threshold percentage of 0.154% based on race and ethnicity:

• Schwarze Frauen müssten im Alter von 34 Jahren untersucht werden.
• Weiße Frauen im Alter von 41 Jahren,
• Hispanische Frauen im Alter von 43 Jahren und
• Amerikanische Indianer oder Alaska-Ureinwohner und asiatische oder pazifische Insulanerinnen im Alter von 43 Jahren.

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, as well as recruited talent start-up funds in Zhejiang Cancer Hospital.

Implications and limitations for practice

Current mammography screening guidelines do not account for racial disparities in breast cancer survival.¹

Breast cancer screening guidelines recommend a starting age for screening that is between 40 and 50 years old and varies depending on the issuing organization. The American Cancer Society recommends a first mammogram for average-risk women starting at age 45 and can begin as early as age 40.²The American College of Obstetricians and Gynecologists recommends initial screening no later than age 50 for average-risk women, but can begin as early as age 40.³And the United States Preventive Services Task Force recommends that screening begin at age 50 for women at average risk of breast cancer.⁴Although the current one

Although screening guidelines are associated with reductions in breast cancer mortality, disparities in risk reduction for Black women remain.

In general, black women had an increased risk of dying from early-stage breast cancer and therefore could be screened up to 8 years earlier than the recommended starting age of 50.

The authors report: "In general, black women were at increased risk of dying from early-stage breast cancer and therefore could be screened up to 8 years earlier than the recommended starting age of 50." Black women reached the risk threshold at age 42, corresponding to white women at age 51, American Indian or Alaska Native and Hispanic women at age 57, and Asian or Pacific Islander women 11 years later at age 61. Race- and ethnicity-adjusted entry ages for black women were consistently lower to achieve similar breast cancer mortality risk, specifically being 6 years earlier for mass screening at age 40 and 7 years earlier for mass screening at age 45.”⁵

In a study published inAnnals of Internal MedicineIn 2021, the Cancer Intervention and Surveillance Modeling Network found that biennial screening between ages 40 and 74 could be associated with a 57% reduction in the breast cancer mortality gap between black and white women.^{NOTEREF _Ref144684990 h * MERGE FORMAT1}

From the study reviewed here, the authors write: "BC mortality depends on many factors, such as differences in the distribution of breast size and density, the quality of screening tests, the host tumor microenvironment, access and quality of treatment, competing mortality, and phenotypic distribution." Prevalence of BC, tumor grading and stage at diagnosis, initiation of breast cancer treatment, type of treatment received, barriers to accessing health care, 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 from early breast cancer in black women younger than the recommended age for mass screening.”⁵

The study results justify the need to adapt current uniform screening guidelines for breast cancer to improve survival and reduce mortality risk.