Woman examining her breasts for cancer
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Another piece of evidence has been added to the longstanding debate about when annual breast cancer screening should begin. Starting at age 40, and continuing to at least age 79, provides the highest reduction in mortality with minimal risks, according to a new study published recently in Radiology.

“The biggest takeaway point of our study is that annual screening beginning at 40 and continuing to at least age 79 gives the highest mortality reduction, the most cancer deaths averted, and the most years of life gained,” said lead researcher Debra L. Monticciolo, MD, professor of radiology at Dartmouth Geisel School of Medicine in Hanover, New Hampshire. “There’s a huge benefit to screening annually until at least 79 and even more benefit if women are screened past 79.”

Breast cancer is the second most common cause of cancer death for women in the U.S. About 4,200 women and 500 men die from the disease annually in this country alone. Screening mammography can reduce breast cancer deaths by 40%, but only 50% or fewer of eligible women actually participate in annual screening. Yet today’s mammography uses less radiation and newer techniques are more accurate, reducing the need for unnecessary biopsies.

“Today’s techniques with digital and digital breast tomosynthesis help diminish recalls from screening by eliminating, in many cases, superimposition of tissues. It helps clarify whether or not a true mass exists, without additional imaging,” Monticciolo told Inside Precision Medicine.

Over the years there has been some debate about when to screen for breast cancer. 

A recommendation by the U.S. Preventive Services Task Force (USPSTF) in 2009 to screen every other year, or biennially, beginning at age 50 led to a decline in screening participation. The USPSTF drafted new recommendations in 2023, suggesting women participate in biennial screening from the age of 40 to 74. The American College of Radiology, the Society of Breast Imaging and the National Comprehensive Cancer Network, recommend annual screening for women at average risk for breast cancer beginning at age 40 and continuing as long as the woman is in good health.

In this study, Monticciolo and colleagues compared the benefits of screening, including mortality reduction, life years gained, breast cancer deaths averted, and its risks—including benign, or unnecessary, biopsies and recall rates—for four different scenarios: biennial screening of women 50 to 74 (the longstanding USPSTF recommendation); biennial screening of women 40 to 74 (the task force’s new draft recommendation); annual screening 40 to 74; and annual screening 40 to 79. CISNET does not offer modeling past age 79.

A review of CISNET (Cancer Intervention and Surveillance Modeling Network) estimates showed the team that annual screening of women aged 40 to 79 with either digital mammography or tomosynthesis showed a mortality reduction of 41.7%. Biennial screening of women aged 50 to 74 and 40 to 74 showed mortality reduction of 25.4% and 30%, respectively. Annual screening of women 40 to 79 years showed the lowest per mammogram false-positive screens (6.5%) and benign biopsies (0.88%) compared to other screening scenarios.

According to the researchers’ analyses, the chance of a woman having a benign biopsy following annual screening is less than 1%, and all recall rates for screening mammography are under 10%. When screening is performed annually with tomosynthesis, the recall rate decreases to 6.5%.

Monticciolo said, “There is overwhelming scientific evidence that breast cancer screening leads to a significant reduction in breast cancer mortality for women aged 40 years and older, and yet it took from 2002 to 2023 for the USPSTF to return to recommending screening for women in their 40’s. It is time for the medical community to recognize that the goal of screening is to prevent cancer death and to move toward maximizing that benefit.”

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