Get Updates

Making Sense of Cancer Headlines

FORCE's XRAYS program, funded by the CDC, is a reliable resource for young breast cancer survivors and high-risk women to navigate through breast cancer research related news and information.

XRAYS logo and women

Breast cancer screening should be tailored to a woman’s risk factors and breast density


This research is relevant for:

Unhecked Breast cancer survivors

Unhecked Women under 45

Checked Women over 45

Unhecked Men with breast cancer

Unhecked Metastatic breast cancer

Unhecked Triple negative breast cancer

Unhecked Previvors

Unhecked BRCA mutation carriers

Unhecked ER/PR +

Unhecked Her2+ breast cancer

Checked Special populations: women with dense breasts; women with family history of breast cancer but no known mutations; women with history of LCIS or multiple breast biopsies

Be a part of XRAYS

XRAYS:  Making Sense of Cancer Headlines

The United States Preventative Services Task Force (USPSTF) recommends a screening mammogram every other year for women ages 50-74 who are at average risk for breast cancer. But do all patients in this category benefit from this screening regimen?


STUDY AT A GLANCE

This study is about:

Using personal breast cancer risk and breast density to determine the frequency of screening mammograms for women over age 50.

Why is this study important?

The widespread use of screening and treatment has resulted in fewer breast cancer deaths for women in the United States. But along with the benefits, some harms come from detection and early intervention.

Study findings: 

  1. Using a computer model, researchers predict that screening mammograms every three years for women who are age 50 and older with average risk for breast cancer and low breast density produces similar or better benefits and harms compared to women who are at average risk and get mammograms every two years.
    • The model predicts that approximately 150 false-positive mammograms will occur to avoid one breast cancer death if women at average risk who have low breast density are screened every two years. It also predicts that with triennial screening, approximately 125 false-positive mammograms will occur to avoid one death due to breast cancer. This means that according to the model predictions, screening women at average risk every three years will lessen the number that receive false-positive mammograms to save one life.
  2. Using a computer model, researchers predict that screening mammograms every year for women who are age 50 and older with higher risk for breast cancer and high breast density produces similar or better benefits and harms compared to women who are at average risk and get mammograms every two years.
    • This means that annual screening mammograms are more beneficial for women with high breast density and high risk for breast cancer, because they have a better balance of benefits (more breast cancer deaths avoided) and harms (false-positive mammograms, benign biopsies) than women at average risk who get mammograms every two years.

What does this mean for me?

This study uses computer models to suggest that breast cancer screening intervals can be tailored to each woman depending on her breast cancer risk and breast density. Researchers did not study actual patients who had screening every one, two or three years. Instead, they modeled and predicted what would happen if these women were to use these screening intervals. More work needs to be done to understand how we can tailor screening intervals for each patient. Currently, patients and their health care providers should work together to determine a patient’s optimal breast cancer screening interval based on her personal breast cancer risk factors.

Questions to ask your health care provider:

  • Do I have dense breasts?
  • What is my breast cancer risk?
  • What risk factors for breast cancer do I have?
  • How can I lower my breast cancer risk?
  • When should I start breast cancer screening?
  • I have a family history of breast cancer; should I start screening mammograms before age 50?
  • I have a mutation in a gene associated with increased breast cancer risk; what other breast screening should I consider?
  • I received a dense breast notification at my last mammogram; what type of breast cancer screening do I need?

IN DEPTH REVIEW OF RESEARCH

Study background:

The 2016 U.S. Preventive Services Task Force (USPSTF) made the controversial recommendation that women aged 50-74 should get screening mammograms every other year, rather than annually. However, do all women in this age group benefit from the same screening mammogram regime? Amy Trentham-Dietz and her colleagues from the University of Wisconsin Carbone Cancer Center and other institutions published work in the Annals of Internal Medicine that addresses this question.

Researchers of this study wanted to know:

Can a woman’s breast density and breast cancer risk be used to determine the optimal time between her screening mammograms?

Population(s) looked at in the study:

Researchers from the Cancer Intervention and Surveillance Modeling Network and the Breast Cancer Surveillance Consortium used three well-established models (Models E, GE, and W) to predict the benefits and harms of screening mammograms for women 50 years and older with various combinations of breast cancer risk and breast densities. This model used data collected from 1975-2010 by the Surveillance, Epidemiology, and End Results (SEER) program. The women modeled were at average or moderate (not greater than four times increased risk) risk for breast cancer. Factors leading to a moderate risk of breast cancer included postmenopausal obesity, a history of benign breast biopsies, and a history of lobular carcinoma in situ (LCIS).  Note that moderate breast cancer risk is not as great as the risk of women with BRCA mutations.  Benefits measured were breast cancer deaths avoided due to screening, and quality-adjusted life-years. Harmful outcomes measured were false positive mammograms, benign biopsies, and overdiagnosis (defined as “screen-detected cancer that would not have been diagnosed in a woman's lifetime in the absence of mammography”).

Study findings: 

  1. Using a computer model, researchers predict that screening mammograms every three years for women who are age 50 and older with average risk for breast cancer and low breast density produces similar or better benefits and harms compared to women who are at average risk and get mammograms every two years.
    • The model predicts that approximately 150 false-positive mammograms will occur to avoid one breast cancer death if women at average risk who have low breast density are screened every two years. It also predicts that with triennial screening, approximately 125 false-positive mammograms will occur to avoid one death due to breast cancer. This means that according to the model predictions, screening women at average risk every three years will lessen the number that receive false-positive mammograms to save one life.
  2. Using a computer model, researchers predict that screening mammograms every year for women who are age 50 and older with higher risk for breast cancer and high breast density produces similar or better benefits and harms compared to women who are at average risk and get mammograms every two years.
    • This means that annual screening mammograms are more beneficial for women with high breast density and high risk for breast cancer, because they have a better balance of benefits (more breast cancer deaths avoided) and harms (false-positive mammograms, benign biopsies) than women at average risk who get mammograms every two years.

Limitations:

Because this study only included information from women who were 50 years and older, the findings do not apply to younger women. Nor did it look at women who are at higher risk of breast cancer due to a genetic mutation such as BRCA that increases breast cancer risk. And finally, because these results are predicted from a computer model, it assumes that patients will adhere to the screening schedule, which may not be the case for all women.  

The conclusions also hinge on how the authors define harm and whether patients would use the same definition. For some women, being called back for additional screening or having a benign biopsy may appear to be a harm.  Other women may prefer to have this additional screening, despite the risk that a detected abnormality turns out to be something other than cancer. This points to a need for personalizing breast screening, not only based on a patient’s risk for breast cancer, but also on her preferences.

It is important to note that this paper used current USPSTF guidelines for breast cancer screening in average risk women as a starting point. These guidelines are controversial and differ from others. Guidelines of numerous other organizations, including the American Cancer Society (ACS), the National Comprehensive Cancer Network (NCCN), the American Medical Association (AMA), the American College of Radiology (ACR), and the American Congress of Obstetricians and Gynecologists (ACOG) recommend annual screening mammograms beginning at younger ages—the ACS recommends age 45, while the other organizations recommend age 40. Recently, the NCCN added that women and their doctors consider using 3D mammography (tomosynthesis), which is not addressed in this study. 

Separate guidelines exist for women known to be at high risk for breast cancer due to mutations in BRCA or other genes associated with increased cancer risk, a strong family history of breast cancer, and/or history of radiation treatment to the chest. In some cases, guidelines recommend combining magnetic resonance imaging (MRI) with mammography. These types of screening were not addressed by this study.

Conclusions:

This study suggests that a woman’s breast density and breast cancer risk can be used to tailor her breast cancer screening interval. These findings are not definitive, because they used computer models to predict the results of being screened at one-, two-, or three-year intervals. However, this research opens discussion on how to tailor screening to benefit each patient individually. Additionally, more work needs to be done to address the limitations of the study, including women who are younger and have mutations in genes that increase cancer risk.

While this study is a step towards personalizing breast cancer screening for women who do not have mutations in BRCA or other genes that increase cancer risk, more work is needed to correctly identify women who would benefit from increased screening. Patients and their health care providers should work together to determine a patients’ optimal screening regimen based on personal and family history of cancer, as well as the patient’s tolerance for the risk of false positives and/or benign biopsies.     

Posted 10/18/16

Share your thoughts on this XRAYS article by taking our brief survey.

References

Trentham-Dietz A, Kerlikowske K, Stout NK, et al. “Tailoring Breast Cancer Screening Intervals by Breast Density and Risk for Women Aged 50 Years or Older: Collaborative Modeling of Screening Outcomes.Annals of Internal Medicine. Published online first on August 23, 2016.  

Siu, AL and the U.S. Preventive Services Task Force. “Screening for Breast Cancer: U.S. Preventive Services Task Force Recommendation Statement.Annals of Internal Medicine. 2016, 164(4): 279-296.  

American Cancer Society. American Cancer Society recommendations for early breast cancer detection in women without breast symptoms. 2015. 

American College of Radiology. ACR and SBI Continue to Recommend Regular Mammography Starting at Age 40. 2015

The American Congress of Obstetricians and Gynecologists. ACOG Statement on Breast Cancer Screening Guidelines. 2016

National Comprehensive Cancer Network. NCCN Framework for Resource Stratification of NCCN Guidelines (NCCN Framework™). 2016.  

Back to XRAYS Home

Find older XRAYS studies and articles

By keyword search:

By date range:

By quarterly digest:

FORCE:Facing Our Risk of Cancer Empowered