Breast cancer is very treatable when caught early, and mammograms, which are X-ray images of breasts, are a reliable screening test to detect it. Now, new draft recommendations released Tuesday from the U.S. Preventive Services Task Force urges all women to get screened every other year, starting at age 40.

The recommendation is based on a review of new evidence by an independent panel of experts at the task force. Until now, women in their 40s have been encouraged to have a conversation with their health care provider about when to start mammograms based on their personal risks.

The task force's previous recommendation was for women to start mammograms at 50, and for women ages 40-49 to consider it, depending on personal risk. The American Cancer Society recommends that women 40 to 44 who are at "average" risk should "have the option" to start screening, but stops short of recommending it for all women, until age 45.

Now, the evidence has shifted in support of recommending mammograms for all women at 40, says, Dr. Carol Mangione, an internal medicine specialist at UCLA who served as previous Chair of the U.S. Preventive Services Task Force and is co-author of the new recommendation.

"New and more inclusive science about breast cancer in women younger than the age of 50 has allowed us to expand our prior recommendation," Mangione says. Mangione points to the rise in breast cancer among people in their forties. "There are a lot more women getting breast cancer, and that influences our recommendation," she says.

The new recommendation applies to all people assigned female at birth who are at average risk of breast cancer.

The task force recommendations are considered the gold standard because they're based on a thorough review of evidence by an independent group of experts. Many doctors follow the task force guidelines. The Affordable Care Act requires most private health insurers to cover annual mammograms, with no cost sharing, making them free to patients.

Breast cancer is the second leading cause of cancer death among women. About 42,000 women and 500 men die from the disease each year, according to the CDC.

"If all women followed our new recommendation, we could reduce mortality from breast cancer in the U.S. by about 20%," says Mangione, saving about 8,000 lives a year. "That's a big reduction in mortality from breast cancer," she says.

Black women are 40% more likely to die from breast cancer, so the new recommendation is "incredibly important" to address this disparity, Mangione says. "Starting at 40 actually creates the most benefit for Black women in our country," she says.

When someone is diagnosed with breast cancer, there are many interactions with the health care system, from screening to biopsy to treatment. "Because of structural racism and health equity problems, there's probably a step off at every single part of that pathway for Black women," Mangione says. "The cumulative effect is they end up with higher mortality."

In order to address this health disparity, the Task Force is "urgently calling" for more research.

Women with a family history or genetic risk factors who are at high risk of breast cancer may start screenings before age 40, and there are separate screening recommendations for women at high risk. But for women at average risk, there's previously been debate about what age to begin and how often.

Mangione says the task force "looked hard" to see if annual screening would save more lives than bi-annual screening. For now, "we found that every other year was the optimal strategy,' she says, though she says more evidence is needed.

"Believe it or not, there's never been a clinical trial in the U.S. that has compared annual to biannual with our current technology and treatments," Mangione says. "This is a big evidence gap." The task force also calls for more research to better understand whether people with dense breasts, which can make breast cancer more difficult to detect, could benefit from additional screening such as breast ultrasound or MRI.

Several medical groups have breast cancer screening recommendations. The American College of Obstetricians and Gynecologists recommends that women at average risk of breast cancer should get a mammogram every 1 to 2 years, beginning at age 40. So, the new draft recommendation from the U.S. Preventive Services Task Force brings the screening recommendations into alignment.

"We're seeing a consensus," Mangione says, that starting at 40 and having mammograms every other year can be beneficial.

The draft recommendation is open for public comment until June 5, 2023.