It has become less deadly, but breast cancer rates are rising sharply in the United States, particularly among younger women and among Asian Americans, according to a study published Tuesday.
The number of cases increased by 1% each year between 2012 and 2021, amid a drastic drop in the mortality rate, which fell by 44% between 1989 and 2022, the American Cancer Society revealed in its biennial report.
Breast cancer is the second most commonly diagnosed cancer in American women and the second leading cause of cancer death in the United States, after lung cancer.
About one in eight women in the United States will be diagnosed with invasive breast cancer in her lifetime, and 21% of American women will die from it.
The report shows that over the last decade, the number of breast cancers has increased more rapidly in women under 50 than in older women (1.4% per year compared to 0.7%), for reasons that are still unclear.
At the same time, Asian-American women have seen the fastest increase in breast cancer rates, followed by Hispanics, which the report said "may be related in part to the influx of new immigrants who are at elevated risk for breast cancer."
Overall, the breast cancer mortality rate has fallen by 441%, from 33 deaths per 100,000 women in 1989 to 19 deaths per 100,000 women in 2022, or 517,900 deaths avoided.
Not all women have benefited equally from decades of medical advances in treatment and early detection.
The death rate has remained unchanged since 1990 among Native American women, while black women have 381% more deaths than white women, despite having 51% fewer cases.
These findings highlight the impact of "social factors" on health and "long-standing systemic racism that has resulted in poorer access to quality care."
The authors of the report recommend increasing ethnic diversity in clinical trials as well as partnerships that promote access to quality screening for the most disadvantaged women.
In April, an independent American organization that issues public health recommendations estimated that women should start having mammograms at the age of 40, not 50, and should have them every two years.