The US Preventive Services Task Force updated its guidelines  to recommend that women begin mammogram screening at age 40 rather than 50.

The change is the result of new scientific evidence, the task force said. The rate of breast cancer among women ages 40 to 49 increased 2% per year, on average, from 2015 to 2019, according to the National Cancer Institute.  Black women are 40% more likely to die from breast cancer than white women and are more likely to develop aggressive forms of breast cancer at a younger age.

Beginning screening at age 40 is estimated to save 20% more women’s lives, according to Dr. John Wong of Tufts University School of Medicine, who is on the task force.

Many other medical groups already recommend annual screenings before age 50, including the American Cancer Society and the American College of Radiology, which recommends yearly screenings starting at 40.

Although the task force’s recommendations weigh the benefits of detecting cancer against the risks of annual scans — including radiation exposure and unnecessary biopsies — radiologists consider those risks to be relatively small. In 2019, around 60% of women ages 40 to 49 reported having a mammogram within the past two years, according to the Centers for Disease Control and Prevention.