Data leads health experts to alter recommendations for addressing breast cancer threat

Dr. Jeff Hersh
·4 min read

Q: I am 41 years old with no family history of breast cancer. Last year my doctor said a mammogram was optional, but this year she said it's recommended. Why the change?

A: Today’s column will focus on breast cancer screening recommendations for women at "average risk," meaning “asymptomatic women… who do not have preexisting breast cancer or a previously diagnosed high-risk breast lesion and who are not at high risk for breast cancer because of a known underlying genetic mutation (such as a BRCA1 or BRCA2 gene mutation or other familial breast cancer syndrome) or a history of chest radiation at a young age.”

Screening recommendations for women at high risk are not the same as those for women at average risk. For certain women at high risk, a magnetic resonance imaging (MRI) test may be the best option, and this should be discussed with their health care provider. It should also be noted that women with dense breast tissue (“relatively high amounts of glandular tissue and fibrous connective tissue and relatively low amounts of fatty breast tissue”) are at a higher risk for developing breast cancer, and mammograms may not be as sensitive for these women (it's harder to interpret a mammogram in a woman with dense breasts), so adding screening with a breast ultrasound or MRI may be considered.

Dr. Jeff Hersh
Dr. Jeff Hersh

One in eight women will develop breast cancer at some point in their lives. Although that has not significantly changed recently, the United States Preventive Services Task Force (USPSTF) reviews breast cancer data regularly to keep its recommendations up to date, including looking for changes in the following:

  • Trends in terms of when women develop breast cancer;

  • Rates of false positive screenings (this occurs when when the screening test suggests there may be cancer, but the more detailed evaluation, typically including a breast biopsy, shows there is none);

  • Sensitivity of screening (the test’s likelihood of being positive in a patient who does have breast cancer);

  • Clinical outcomes for women who are diagnosed with breast cancer.

These changes may occur for many reasons, including:

  • Breast cancer prevalence at a given age may change over time (although the reasons for that are not well understood);

  • Screenings may become more specific and sensitive due to technology improvements (for example, data shows that 3D mammography is more sensitive and has a lower false positive rate than 2D mammography);

  • There may be improvements in clinical outcomes because treatments improve, and hence there may be even greater benefits obtained from making an earlier diagnosis.

Because of this, screening recommendations have changed periodically over the years. For example, the USPSTF recommendation in 2002 was “screening mammography, with or without clinical breast examination (CBE), every 1-2 years for women aged 40 and older." But just seven years later, the recommendation was for “biennial screening mammography for women 50-74 years,” while noting “current evidence is insufficient to assess the additional benefits and harms of CBE.

Seven years after that, in 2016, the recommendation was still “biennial screening mammography for women aged 50 to 74 years,” but they then added “the decision to start screening mammography in women prior to age 50 years should be an individual one. Women who place a higher value on the potential benefit than the potential harms may choose to begin biennial screening between the ages of 40 and 49 years. For women who are at average risk for breast cancer, most of the benefit of mammography results from biennial screening during ages 50 to 74 years.”

Data from 2015 to 2019 showed a 2% increase in breast cancer in women in their 40s each year, demonstrating breast cancer at younger ages is becoming more common. Hence, the 2024 recommendation is now “biennial screening mammography for women aged 40 to 74 years,” also noting that “evidence is insufficient to assess the balance of benefits and harms of supplemental screening for breast cancer using breast ultrasonography or MRI in women identified to have dense breasts on an otherwise negative screening mammogram.”

I hope this explains why the recommendations for breast cancer screening have recently changed, and gives readers an idea of the complex considerations the USPSTF must balance when making/changing recommendations. Please discuss what screening is indicated for you with your health care provider, and when it should begin. It should also be noted here that the cost of screening should not be an issue, as one of the many benefits of the Affordable Care Act (ACA, often called Obamacare) is that “any preventive service receiving a Grade A or B from the USPSTF must be covered at 100% by most health insurers.”

Jeff Hersh, Ph.D., M.D., can be reached atDrHersh@juno.com.

This article originally appeared on MetroWest Daily News: Dr. Hersh: Breast cancer screening advice has changed over the years