Breast cancer incidence trends vary by age, race, and stage in older women

Breast cancer incidence trends vary by age, race, and stage in older women | Image Credit: © vectorfusionart - © vectorfusionart - stock.adobe.com.

Racial, ethnic, and stage-specific patterns of breast cancer (BC) differ between age groups, according to a recent study published in JAMA Network Open.¹

Rising BC rates

Varying rates of BC incidence have been reported over time, including rates among patients aged under 40 years increasing by 0.5% per year from 2004 to 2019.² These trends have also been observed to differ based on demographic characteristics in this age group, but there has been little research examining trends in older women, which is one of the fastest growing US populations.¹

“It is essential to examine trends over time across screening-relevant age groups to determine whether observed trends align with changes in mammography participation or indicate other contributing factors to BC incidence in older women,” wrote investigators.

Assessing BC in older women

The study was conducted to evaluate BC incidence rates in US women aged at least 65 years. Data was obtained from the US Cancer Statistics public use database, a cancer surveillance system including up to 99% of the US population.

Each year, new cancer diagnoses are obtained from medical facility records and combined. Medical and administrative records are utilized to record demographic data and medical information. Additionally, SEER*Stat software was used to collect age-adjusted data about BC incidence across 19 age groups.

BC cases in women aged at least 65 years between January 1, 2001, and December 31, 2019, were included in the analysis. Relevant age groups included 65 to 74 years, 75 to 84 years, and 85 years or older. Among these groups and the overall population, rates of BC were stratified by race and ethnicity, metropolitan status, geographic region, and stage at diagnosis.

Race and ethnicity categories included Hispanic, American Indian, Asian, Black, and White. Rural-Urban Continuum Codes were assessed to determine metropolitan status as metropolitan, nonmetropolitan, or unknown. Stages at diagnosis included regional, distant, and unknown. Finally, the US Census determined the geographic region.

Incidence rates and patient demographics

Invasive or in situ BC was reported in 2,278,611 patients during the study period, 54.9% of whom were aged 65 to 74 years, 5.2% Hispanic, 9% Black, and 80.1% White. In patients aged 65 to 74 years, the age-adjusted BC incidence rate was 530.4 per 100,000 persons.

In comparison, incidence rates of 515.3 and 376.8 per 100,000 persons were reported in patients aged 75 to 84 years and at least 85 years, respectively.

Similar molecular subtype distribution was reported across age groups, remaining consistent between the 2011 to 2014 and 2015 to 2019 periods. Triple-negative BC was significantly more common in Black women vs other races and ethnicities in all age groups.

Trends in BC incidence over time

A 0.4% increase per year in BC incidence was observed in women aged 65 to 74 years between 2001 and 2019. However, no significant changes were observed among those aged 75 to 84 years, and a decrease of 1.1% per year was reported in women aged at least 85 years.

Among patients aged 65 to 74 years and those aged 75 to 84 years, White women had the greatest BC incidence between 2001 to 2019. However, in those aged 85 years and older, the highest incidence was observed in Black women.

Racial and ethnic minority groups had greater increases in BC incidence than White women among patients aged 65 to 74 years, with average annual percent changes (AAPCs) of 1.6%, 1.8%, 2.2%, and 1.4% for Black, American Indian, Asian, and Hispanic women, respectively.

In those aged 75 to 84 years, AAPCs were 1% for Black women and 0.9% for Asian women, while other racial and ethnic groups did not show significant changes. In those aged at least 85 years, White and Hispanic women underwent decreases in incidence, with AAPCs of -1 and -1.3, respectively. Other racial and ethnic subgroups did not experience significant changes.

Need for targeted analysis and interventions

These results highlighted varying rates of BC incidence in patients aged 65 years and older based on race and ethnicity. Investigators also noted differences based on factors such as stage at diagnosis.

“Together, these findings underscore the importance of age- and race and ethnicity–specific analyses to address disparities and improve outcomes in older women,” wrote investigators.

References:

1. Lee Argov EJ, Lui ML, Karr AG, Tehranifar P, Kehm RD. Breast cancer incidence trends in older US women by race, ethnicity, geography, and stage. JAMA Netw Open. 2025;8(6):e2516947. doi:10.1001/jamanetworkopen.2025.16947
2. Cathcart-Rake EJ, Ruddy KJ, Bleyer A, Johnson RH. Breast cancer in adolescent and young adult women under the age of 40 years.JCO Oncol Pract. 2021;17(6):305-313. doi:10.1200/OP.20.00793