Research table: Mammography screening for women 40-49
This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.
Introduction: For women 40-49, breast cancer screening with mammography saves lives, but the benefits are less than for older women.
The U.S. Preventive Services Task Force meta-analysis of 8 randomized controlled trials found mammography modestly reduced the risk of breast cancer mortality (death) in women 40-49 .
The American College of Physicians reviewed 117 studies and found mammography reduced breast cancer mortality in women 40-49, but the risk of false positive results was high .
Recommendations for mammography screening
The National Comprehensive Cancer Network recommends routine mammography for women starting at age 40 .
The American Cancer Society states women ages 40-44 should have the option to have a mammogram every year . It recommends routine mammography starting at age 45 .
The U.S. Preventive Services Task Force and the American College of Physicians recommend women 40-49 make informed decisions about mammography [5-6]. This means discussing the pros and cons of mammography with a health care provider. Then, together with the health care provider, making decisions about when to start breast cancer screening with mammography and how often to get screened.
Learn more about mammography in women 40-49.
Learn about weighing the benefits and risks of mammography.
Women Should Have Access to and Coverage for Mammography
Susan G. Komen® believes all women should have access to regular screening mammograms when they and their health care providers decide it is best based on their personal risk of breast cancer. In addition, screening should be covered by insurance companies, government programs and other third-party payers.
Study selection criteria: Large randomized controlled trials and meta-analyses.
Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.
Age at Screening
Relative Risk of Breast Cancer Mortality (Death) in Women Who Got Screening Mammography Versus Women Who Did Not
Randomized controlled trials
Age Trial (United Kingdom) 
Canadian National Breast Cancer Screening Study 
Gothenburg Breast Screening Trial 
Kerlikowske et al. 
U.S. Preventive Services Task Force 
Cochrane Collaboration 
age less than 50
*The combined relative risk for the 3 studies with good methodology was 0.87 (0.73-1.03).
- Nelson HD, Fu R, Cantor A, Pappas M, Daeges M, Humphrey L. Effectiveness of breast cancer screening: systematic review and meta-analysis to update the 2009 U.S. Preventive Services Task Force recommendation. Ann Intern Med. 164(4):226-35, 2016.
- Armstrong K, Moye E, Williams S, Berlin JA, Reynolds EE. Screening mammography in women 40 to 49 years of age: a systematic review for the American College of Physicians. Ann Intern Med. 146(7):516-26, 2007.
- National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Breast cancer screening and diagnosis, Version 1.2021. http://www.nccn.org, 2021.
- American Cancer Society. American Cancer Society recommendations for the early detection of breast cancer. https://www.cancer.org/cancer/breast-cancer/screening-tests-and-early-detection/american-cancer-society-recommendations-for-the-early-detection-of-breast-cancer.html, 2021.
- Qaseem A, Lin JS, Mustafa RA, et al. for the Clinical Guidelines Committee of the American College of Physicians. Screening for breast cancer in average-risk women: a guidance statement from the American College of Physicians. Ann Intern Med. 170(8):547-560, 2019.
- U.S. Preventive Services Task Force. Screening for breast cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 151(10):716-726, 2009.
- Duffy SW, Vulkan D, Cuckle H, et al. Effect of mammographic screening from age 40 years on breast cancer mortality (UK Age trial): final results of a randomised, controlled trial. Lancet Oncol. 16(9):1123-1132, 2020.
- Miller AB, Wall C, Baines CJ, Sun P, To T, Narod SA. Twenty five year follow-up for breast cancer incidence of the Canadian National Breast Screening Study: randomized screening trial. BMJ. 348:g366, 2014.
- Bjurstam NG, Björneld LM, Duffy SW. Updated results of the Gothenburg Trial of Mammographic Screening. Cancer. 122(12):1832-5, 2016.
- Alexander FE, Anderson TJ, Brown HK, et al. 14 years of follow-up from the Edinburgh randomised trial of breast-cancer screening. Lancet. 353(9168):1903-8, 1999.
- Kerlikowske K, Grady D, Rubin SM, et al: Efficacy of screening mammography: A meta-analysis. JAMA 273:149-154, 1995.
- Gøtzsche PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database Syst Rev. 6:CD001877, 2013.