Breast Cancer Incidence Rising, Disparities Persist

Breast cancer incidence has been on the rise, particularly among White women under age 50, but breast cancer deaths — for some, but not all, populations — have been steadily decreasing, according to a biennial update from the American Cancer Society (ACS).

The ACS update, which underscores the persistence of racial and ethnic disparities in breast cancer incidence and outcomes, noted an overall 1% annual increase in breast cancer incidence from 2012 to 2021. The additional cases were largely composed of localized-stage and hormone receptor (HR)–positive disease, which generally have better prognoses than more advanced and HR–negative disease.

Deaths from breast cancer, however, declined from 1989 to 2022, with an overall drop of 44%. That percentage drop “translates to almost 518,000 fewer women dying from breast cancer in the United States during this time,” Angela N. Giaquinto and ACS colleagues noted in the report, published last week in CA: A Cancer Journal for Clinicians.

“This progress is the result of advances in treatment and earlier detection through screening,” the authors wrote, while stressing that “these interventions have not been disseminated equally.”

The ACS also published an educational companion — Breast Cancer Facts & Figures 2024-2025 — that provides additional insights about trends in breast cancer and steps needed to bolster prevention, detection, and treatment advances.

Incidence and Mortality

Although the overall annual increase in breast cancer incidence from 2012 to 2021 was 1%, the increase was steeper among women under age 50, at 1.4% annually vs 0.7% among those aged 50 or older.

Asian American/Pacific Islander women had the greatest increases in breast cancer incidence among both age groups, with a 2.7% annual increase for those aged under 50 and a 2.5% increase for those aged 50 or older. This group, however, had the second lowest breast cancer rate in 2000 at 57.4 cases per 100,000 persons, but the highest rate in 2021 at 86.3 cases per 100,000, alongside White women (86.4 cases per 100,000). Black women were not far behind at 81.5 cases per 100,000.

Black women were least likely to be diagnosed with localized-stage breast cancer and most likely to be diagnosed with distant-stage or unstaged cancer, with American Indian/Alaska Native women not far behind.

Despite the rising incidence of breast cancer, death rates from the disease have gone down considerably overall from about 33 deaths per 100,000 women in 1989 to 19 deaths per 100,000 in 2022.

However, not all women have experienced these survival gains equally, Giaquinto and colleagues noted.

Since 1990, the mortality rate has remained unchanged among American Indian/Alaska Native women. Black women, however, have experienced a 38% higher mortality rate than White women, despite having a 5% lower incidence of breast cancer.

In fact, Black women have the lowest survival of any racial and ethnic group for every breast cancer subtype and stage of disease except localized disease.

Additional key findings from the report:

• In 2024, an estimated 310,720 new invasive breast cancers and 56,500 cases of ductal carcinoma in situ will be diagnosed among women in the United States, and an additional 2790 cases will be diagnosed in men.
• On the mortality front, in 2024, approximately 42,250 women are expected to die of breast cancer; 530 breast cancer deaths are anticipated in men.
• As for the lifetime risk for breast cancer, approximately one in eight women in the United States (13.1%) will be diagnosed with invasive breast cancer; 1 in 43 (2.3%) will die from the disease.
• The 5-year relative survival rate for breast cancer is 91%, but that drops to 86% at 10 years and 81% at 15 years.
• The 5-year relative survival rate is over 99% for breast cancer diagnosed at a localized stage but drops to 87% for regional-stage and 32% for distant-stage disease.
• American Indian/Alaska Native women have a 10% lower breast cancer incidence than White women but 6% higher mortality.

Similar to the ACS report, a recent study published in JAMA Network Open reported rising breast cancer incidence among US women aged 20-49 years of different races in different age groups over the past two decades.

The increased incidence of breast cancer in younger women “is an area of concern and an area where we really need to spend more effort trying to understand why,” said lead study author and breast surgeon Adetunji T. Toriola, MD, PhD, MPH, of Washington University in St Louis, St Louis, Missouri.

Although reproductive and lifestyle factors, such as weight gain, diet, and physical activity, may contribute to the growing breast cancer incidence in younger women — and preliminary findings from Toriola’s own research suggest that reproductive factors may be a particularly strong driver — environmental factors, including exposure to forever chemicals, may also play a role.

Early-life factors, such as exposure to toxins, remain an underexplored area, Toriola noted, stressing the importance of teasing out the long-term effects of environmental exposures in puberty and during adolescence.

Overall, the trends observed both in this study and the ACS report highlight the need for enhanced prevention efforts that address racial disparities as well as the rising incidence in young women, said Toriola, also professor of surgery at the Washington University Institute of Public Health, St Louis, Missouri.

For now, Toriola urges women to “engage with mammographic screening as soon as qualified” as per guidelines. Women at average risk should go for screening beginning at age 40, and those with a family history or other risk factors should talk to their physician about earlier screening, he said.

Giaquinto is employed by the ACS, which receives grants from private and corporate foundations, including foundations associated with companies in the health sector, for research outside of the submitted work. Toriola reported having no disclosures.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape Medical News, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X @SW_MedReporter.