Breast cancer mortality rates may have stopped declining in women older than 74 years and younger than 40 years, according to a recent study published by Monticciolo and Hendrick in the Journal of Breast Imaging.
Background
Breast cancer is the second leading cause of cancer-related mortality among U.S. women, with over 42,000 women dying of the disease in 2024. Prior to 1990, breast cancer rates among women had been rising, and breast cancer mortality rates had been flat or increasing. However, since 1990, there had been a steady decline in breast cancer mortality rates, which public health officials attributed to the widespread use of mammograms and improvements in breast cancer therapy.
Study Methods and Results
In the study, investigators used data collected and maintained by the National Center for Health Statistics since 1990 to assess breast cancer mortality rates.
The investigators found that among U.S. women, the breast cancer mortality rates decreased steadily by 43.5% from 1990 to 2022. Most recently, these rates have fallen by 1.23% per year between 2010 and 2022—the lowest rate of decrease recorded since 1990. Among those aged 20 to 39 years, breast cancer mortality rates declined by 2.79% per year from 1990 until 2010, but remained level since 2010.
Further, the breast cancer mortality rate decreased by 1.26% per year from 1993 to 2013 among women aged 75 years and older. However, the rate stopped declining in 2013. Among Asian, Hispanic, and Native American women of all ages, breast cancer mortality rates stopped declining since 2009, 2008, and 2005, respectively.
Prior studies indicated that breast cancer mortality rates stopped declining among women younger than 40 years in 2010. In the recent study, the investigators found that mortality rates no longer declining among White women younger than 40 years and older than 74 years as well as unfavorable trends among Hispanic women aged 20 to 39 years and Asian, Hispanic, and Native American women aged 75 years and older were primarily responsible for the end of mortality rate decline in both younger and older patient groups.
The investigators argued that mortality rates have stopped declining among women younger than 40 years and older than 74 years because of increases in stage IV breast cancers at diagnosis in these two age groups—which has a 5-year survival rate of 31%.
Breast cancer mortality rate ratios among Black vs White women demonstrated the widest gap in women younger than 40 years, representing a need for alternatives to current breast cancer risk assessment, screening, and treatment strategies among younger Black women.
Conclusions
The findings highlighted that increasing rates of late-stage breast cancer diagnoses may be a critical reason breast cancer mortality rates are no longer declining as they once did. The investigators hypothesized that this may be the result of health-care protocols. Although the health-care community currently recommends a breast cancer assessment in all women by age 25 years, breast cancer screening is only recommended for those younger than 40 years at higher-than-average risk. Some guidelines discourage screening among women older than 74 years.
“The fact that breast cancer mortality rates have stopped declining for women over age 74 is an alarming new trend,” underscored lead study author Debra Monticciolo, MD, of the Baylor Scott & White Central Texas Foundation for Imaging Research and Education. “This is in addition to women under age 40 no longer seeing mortality rates decline from breast cancer. These groups are exactly those discouraged from breast cancer screening by some U.S. guidelines,” she concluded.
Disclosure: For full disclosures of the study authors, visit academic.oup.com.
