Rates of breast cancer — the second leading cause of cancer deaths in U.S. women — climbed by 1 percent a year from 2012 to 2021, and even more sharply among women under age 50 and among Asian American/Pacific Islander women of all ages, according to an American Cancer Society report published on Tuesday.
The biennial report is among the most comprehensive and detailed studies of breast cancer occurrence over recent years. One in 50 U.S. women will develop invasive breast cancer by the age of 50, the authors said, based on National Cancer Institute calculations.
The sharpest increases in young adults by age during the decade were among women in their 20s, whose rate increased by about 2.2 percent a year, though their absolute risk remains very low, at about 6.5 per 100,000 women.
Among Asian American/Pacific Islander women, who historically also have had a low prevalence of the disease, rates increased by 2.7 percent a year among those under 50, and by 2.5 percent a year among older women.
Cancer is generally considered a disease of aging, and that hasn’t changed: The vast majority of breast cancer cases and deaths still occur among older women. But the new study is one of several documenting a troubling uptick in malignancies among younger Americans.
These so-called early-onset cancers pose special challenges. Striking in early adulthood or midlife, they tend to be aggressive yet are often missed because they are not expected, and routine screenings are aimed at older adults.