Women at average risk for breast cancer should begin mammogram screening at age 40 instead of 50, according to updated recommendations from the U.S. Preventative Services Task Force (USPSTF). This is the final adoption of draft guidance released last May. The recommendations and accompanying materials were published today in JAMA.

The updated guidance was generally applauded by advocates, but some think it doesn’t go far enough and are worried about equitable access to screening and treatment. On the other hand, expanded screening raises concerns about overdiagnosis leading to anxiety and unnecessary procedures.

The new guidance builds on the 2016 recommendations, which said that women at average risk should receive mammograms every other year from age 50 to 74 and advised those between the ages of 40 and 50 to make  individual decisions about screening with their health care providers based on their personal needs and preferences.

The update is supported by a review of additional medical research published over the past decade, which includes more studies of breast cancer in younger women. The recommendations received a B grade, meaning there is “high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial.”

The recommendations apply to anyone assigned female at birth, including transgender men and nonbinary people. They also apply to women who have factors associated with increased risk for breast cancer, such as family history, but not to those with a high risk, for example women who carry harmful BRCA gene variations, those who received high-dose radiation therapy to the chest at a young age and those who have had breast cancer in the past or high-risk breast lesions on previous biopsies.

The guidance states that current evidence is insufficient to assess the balance of benefits and harms of screening for women ages 75 years and older. The Task Force also concluded that the evidence is insufficient to assess the benefits and harms of supplemental screening, such as ultrasound or magnetic resonance imaging, for women with dense breasts.

One of the potential harms of expanded screening is overdiagnosis, meaning detection of breast abnormalities that never would have led to health problems or impacted survival, which can lead to anxiety, unnecessary biopsies and side effects from unneeded treatment. Such concerns prompted a change to USPSTF guidance in 2009 that raised the recommended screening age from 40 to 50 and left screening between ages 40 and 49 as an individual decision.

The Task Force authors emphasized that screening alone is not enough, and it must be followed by confirmatory tests and treatment, if indicated.

“To achieve the benefit of screening and mitigate disparities in breast cancer mortality by race and ethnicity, it is important that all persons with abnormal screening mammography results receive equitable and appropriate follow-up evaluation and additional testing, inclusive of indicated biopsies, and that all persons diagnosed with breast cancer receive effective treatment,” they wrote in their recommendation statement.

This update brings the USPSTF recommendations in line with other organizations. The American Cancer Society (ACS) recommends that women ages 45 to 55 should receive mammograms every year, women 55 and older should do so every other year and women ages 40 to 44 should have the option to screen. In 2022, the National Comprehensive Cancer Network (NCCN) recommended annual mammograms for average-risk women ages 40 and older. In fact, NCCN suggests that women should begin assessing their risk for breast cancer risk as early as age 25. The American College of Radiology recommends annual mammograms starting at age 40, along with earlier screening for women at higher risk and supplemental screening for those with dense breasts. None of these organizations put an upper limit on the screening age.

USPSTF guidelines carry extra weight, however, because the Affordable Care Act requires health insurers to cover preventive health services with an A or B grade.

“The USPSTF decision today is a critical change concerning women’s health and the fight against breast cancer, acknowledging that women in their 40s will benefit from mammography screening, and sending a strong message to referring physicians and women that breast cancer screening should begin earlier than age 50,” ACS CEO Karen Knudsen, PhD, said in a statement. “We are encouraged that among the reasons for the USPSTF changes in their breast cancer screening recommendations include eliminating health disparities, especially among Black women, who are 40% more likely to die of breast cancer compared with white women and have a higher risk of aggressive breast cancers at all ages.”

But Knudson added that ACS is disappointed that the updated USPSTF recommendations do not include older women. “Millions of women over age 75 are in very good health and are expected to live many more years during which their risk of breast cancer remains high,” she said. “The ACS does not support stopping screening for anyone with a 10+ year life expectancy irrespective of age.”

Others criticized the USPSTF guidance for recommending mammograms every other year rather than annually, meaning more frequent screening may not be covered by insurance.

“Annual screenings provide the best opportunity for individuals to detect their cancers early when treatment options are easier and survival rates are higher,” Paula Schneider, president and CEO of the Susan G. Komen advocacy organization said in a statement. “Everyone deserves a personalized breast cancer screening plan tailored to their unique needs, determined in partnership with their trusted health care provider.”

Laura Schmidt contributed to reporting for this article.

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