Breast Cancer Mortality Rates Are No Longer Declining In Younger Women

For many years, the mortality rates of breast cancer were on the decline among younger women. However, this trend appears to be reversing, according to a study—and the rates may begin to increase more.

“It’s clear that mortality rates in women under 40 are no longer decreasing,” said study lead author R. Edward Hendrick, PhD, clinical professor from the Department of Radiology at the University of Colorado School of Medicine in Aurora, Colorado, in a press release. “I estimate that in two to three years, the mortality rate will be increasing significantly in these women.”

The retrospective review included female breast cancer mortality rates from the National Center for Health Statistics spanning 1969 to 2017 for all races and by race, as well as age- and delay-adjusted invasive breast cancer incidence rates from the Surveillance, Epidemiology, and End Results program. Breast cancer rates of mortality by age decade in women aged 20 to 79 years and in women aged 20 to 39 years and 40 to 69 years were evaluated.

Breast cancer mortality rates declined from 1989 to 2010 in each age decade from 20 to 79 years, with declines ranging from 1.5% to 3.4% per year (P<0.001 for each). And after 2010, each age decade from 40 to 79 years had declining rates of mortality, ranging from 1.2% to 2.2% per year (P<0.001 for each).

However, in the younger age decades, rates of mortality began to increase. After 2010, in women aged 20 to 29 years, breast cancer mortality rates increased by 2.8% per year (P=0.11), and in women aged 30 to 39 years, 0.3% per year (P=0.70). The authors called the increases “nonsignificant” and noted that the “results [were] attributable primarily to changes in mortality rates in White women.”

“A contributing factor is that distant-stage breast cancer incidence rates increased by more than 4% per year after the year 2000 in women aged 20–39 years,” the researchers added.

The study was published in Radiology.

According to Dr. Hendrick, “Our hope is that these findings focus more attention and research on breast cancer in younger women and what is behind this rapid increase in late-stage cancers.”

Of note, the researchers also suggested that older women may benefit from more frequent screenings. “In women aged 70–79 years, high and significantly increasing breast cancer incidence rates, along with higher rates of late-stage disease, suggest that continued screening in this age cohort would be beneficial,” they wrote in their conclusion.