Breast Cancer Mortality Drops in US, but Pockets of Racial Disparities Remain

By: Mary Ellen Schneider

From: cancertherapyadvisor.com

Breast cancer mortality is down overall, but investigators saw increasing rates for Latin, American Indian/Alaska Native, and Asian women in a significant proportion of counties.

The mortality rate for breast cancer has declined in the US over the past 20 years, but some counties have seen mortality increases for women who are American Indian or Alaska Native, Asian, and Latina, according to findings published in the Journal of the National Cancer Institute.

“Our detailed estimates highlight disparities in breast cancer mortality and lend insight into counties and racial and/or ethnic groups most in need of improved breast cancer care,” the researchers wrote.

The researchers examined country-level trends in age-standardized breast cancer mortality by race/ethnicity from 2000 to 2019 for women living in the US. The researchers used de-identified death records from the US National Vital Statistics System and population estimates from the US National Center for Health Statistics to analyze causes of death. Estimates were age-standardized using the 2010 US Census.

Race/ethnicity was stratified into 5 mutually exclusive populations: American Indian or Alaska Native (AIAN), Asian and Native Hawaiian or Pacific Islander (Asian), Black, Latina or Hispanic (Latina), and White.

Nationally, breast cancer mortality declined from 33.6 to 24.8 deaths per 100,000 women over the study period, an absolute change of −8.9. The mortality rate decreased across each age group studied and among all racial and ethnic populations in the analysis. However, among women 50 to 74 years, the absolute decreases were smallest in Asian (−7.7) and AIAN (−9.6) populations. Additionally, there was an increase in mortality rates for Asian women aged 75 and older, with the breast cancer mortality rate climbing from 71.9 to 80.7 per 100,000. Black women 75 years or older had the highest age-standardized breast cancer mortality rate in 2019 at 187.4 deaths per 100,000.

At the county level, researchers found “wide racial and/or ethnic disparities” in breast cancer mortality.

Among women younger than 50 years, 16.4% of counties had an increase in breast cancer mortality rates for Latina women, with a median absolute increase of 0.23 deaths per 100,000. Researchers also found increases in the under-50 population for AIAN women in 38.2% of counties, for Asian women in 6.9% of counties, and for White women in 1% of counties.

Among women aged 50 to 74 years, mortality rates increased in 22.8% of counties for AIAN women, with a median absolute increase of 4.4 deaths per 100,000. Among Asian women in this age range, rates increased in 9.7% of counties, with a median absolute increase of 3.3 deaths per 100,000. For Latinas aged 50 to 74 years, there was an increase in 13.1% of counties at a median absolute increase of 2.2 deaths per 100,000.

Researchers found that the largest county-level breast cancer mortality increases were among AIAN and Asian women aged 75 years and older. The median absolute increase for AIAN women in this age range was 15.2 deaths per 100,000, and 38.8% of counties had increased mortality rates. The median absolute increase was 14.1 breast cancer deaths per 100,000 for Asian women aged 75 years and older, and 88.3% of countries had increased mortality rates.

“This pattern may reflect the effects of an aging population, since breast cancer incidence and mortality increase in older age groups,” the researchers wrote. “Older women are often underrepresented in clinical trials of breast cancer treatment. As a result, there are limited data to inform clinical practice, which is complicated by competing comorbidities and patient preferences.”

Redlining practices, which restrict mortgage lending based on race/ethnicity, as well as differences in Medicaid eligibility and health professional shortages are all potential factors in the county-level mortality disparities, the researchers wrote.