Breast cancer mortality rates have plunged in recent decades thanks in large part to improvements in screening and treatment options — but the number of new cases continues to rise.
Overall, breast cancer mortality rates have declined 44 percent since 1989, averting an estimated 517,900 deaths, according to a new study published in CA: A Cancer Journal for Clinicians.
But breast cancer incidence, or the number of new cases diagnosed, has climbed 1 percent every year over the past decade. During this period, cases climbed even faster among women under 50 — at 1.4 percent annually — and among people who identify as Asian American or Pacific Islander — by 2.5 to 2.7 percent a year.
“The encouraging news is breast cancer mortality rates continue to decrease, thanks to advances in early detection and treatment,” said the lead study author, Angela Giaquinto, an associate scientist at the American Cancer Society, in a statement. “But future progress may be thwarted by increasing incidence, especially among younger women, and consequences of the COVID-19 pandemic, such as delayed diagnosis due to interruptions in screening.”
Minority Women Disproportionately Die of Breast Cancer
For the study, researchers examined data on breast cancer cases and deaths from the National Cancer Institute and the U.S. Centers for Disease Control and Prevention.
Even though the overall mortality trend is a positive one, progress has been uneven, and certain groups are dying at disproportionate rates, the study findings suggest.
For example, American Indian and Alaskan Native women are 10 percent less likely to get diagnosed with breast cancer than white women, but 6 percent more likely to die of breast cancer.
Later diagnosis may explain this disparity: Only 51 percent of Native women older than 40 have had a mammogram within the past two years, compared with 68 percent of white women.
Similarly, Black women have a 38 percent higher breast cancer mortality rate than white women, even though they have a 5 percent lower incidence rate, the new study also found. Black women also have lower survival rates than white women for every type of breast cancer except localized disease, the mildest and earliest cases that are easier to treat.
Among women under 50, new cases have climbed 50 percent since 2000 among Asian American and Pacific Islander women, the study also found. That means Asian women are now tied with white women for the highest breast cancer incidence rates, at 86 cases per 100,000.
One limitation of the new study is that demographic information may be insufficient or inaccurate, especially for people who identify with more than one racial or ethnic group or who don’t see themselves falling neatly into the categories commonly used in government records, the study authors noted.
Why Younger Women Are Getting Breast Cancer
The rise in breast cancer among young women is likely due to a number of factors, says Dawn Hershman, MD, a professor and the deputy director of the Herbert Irving Comprehensive Cancer Center at Columbia University Medical Center in New York City.
“Clearly changes in lifestyle — less physical activity, increased body mass index, increased alcohol use, increased stress, and decreased sleep — may all contribute,” says Dr. Hershman, who wasn’t involved in the new study.
It’s also possible that increased screening is contributing to the rise in new cases, Hershman says. “There may be a contribution of how we screen, improved imaging for women with dense breasts, and more awareness of earlier screening for women with family histories that may also be contributing,” Hershman says.
Earlier this year, the U.S. Preventive Services Task Force updated its breast cancer screening guidelines to recommend that women get mammograms every two years starting at age 40. The American College of Radiology also recommends starting at 40, but advises women to get annual mammograms and to start even younger if they’re at high risk.
People at higher risk include those with a family history of breast cancer, and they may want to talk to their doctor about whether they need to start screening sooner — ideally starting when they are 10 years younger than when their relative got diagnosed, says Richard Bleicher, MD, a professor and the chief of breast surgery at Fox Chase Cancer Center in Philadelphia.
“Unfortunately, we cannot completely prevent the disease, even with the healthiest of habits, and so early detection may be the next best step,” says Dr. Bleicher, who wasn’t involved in the new study. “This involves getting screened appropriately.”
Healthy lifestyle choices can also help with prevention, and your survival odds if you do develop breast cancer, Bleicher adds. “This includes maintaining a lean weight, not smoking, eating a healthy diet, limiting stress, and getting good sleep,” Bleicher says. “These healthy lifestyle choices minimize risk, but continuing those behaviors helps a person's survival odds even once diagnosed with breast cancer.”
