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Home > Understanding Breast Cancer > Breast Cancer Research > Table 30a: Breast cancer screening with mammography for women 40–49

  


Table 30a: Breast cancer screening with mammography for women 40–49

This summary table contains detailed information about research studies. Summary tables offer an informative look at the science behind many breast cancer guidelines and recommendations. However, they should be viewed with some caution. In order to read and interpret research tables successfully, it is important to understand some key concepts. Learn how to read a research table.

Introduction: For women 40 to 49, mammography screening saves lives, but the benefits are less than for older women.   

The U.S. Preventive Services Task Force meta-analysis of eight randomized controlled trials found mammography modestly reduced the risk of breast cancer mortality (death) in women 40 to 49 [1]. The Task Force found that to prevent one breast cancer death, 1,904 women 40 to 49 would need to be screened with mammography [1]. A review of 117 studies for the American College of Physicians found that while mammography reduced breast cancer mortality in women 40 to 49, the risk of false positive results was quite high [2].  

Recommendations for mammography screening for women 40 to 49

Weighing the benefits and risks, the U.S. Preventive Services Task Force no longer recommends routine mammography for women 40 to 49 [3]. Instead, the Task Force encourages women 40 to 49 to make informed decisions with their health care providers about when to start mammography screening [3]. Likewise, the American College of Physicians recommends mammography decisions for a woman 40 to 49 be based on her breast cancer risk profile and her own preferences (after she weighs the potential benefits and harms of screening mammography) [4].  

Most major health organizations, including the American Cancer Society and the National Cancer Institute, feel the modest survival benefit of mammography in women 40 to 49 outweighs the risk of false positive results. All recommend routine screening mammograms for women at average risk beginning at age 40.  

Learn more about mammography in women 40 to 49

Learn about the debate over mammography for women of any age.  

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. 

Study 

Study Population
(number of participants) 

Follow-up 
(years) 

Age at Screening 

Relative Risk of Breast Cancer Mortality in Women who Were Screened with Mammography Compared to Women who Were Not
 RR (95% CI) 

Randomized controlled trials 

Age Trial (United Kingdom) [5]

161,196

11

age 39-48

0.83
(0.66-1.04)

Canadian National Breast Cancer Screening Study [6]

50,643

25

age 40-49

1.09 
(0.80-1.49)

HIP-study [1]

27,626

18

age 40-49

0.78
(0.56-1.08)

Gothenburg Breast Screening Trial [7]

26,034

14

age 39-49

0.70
(0.46-1.06)

Malmo [1]

25,966

13

age 43-49

0.73
(0.51-1.04)

Stockholm [1]

22,371

14

age 40-49

1.47
(0.77-2.78)

Ostergotland [1]

20,805

17

age 40-49

1.05
(0.64-1.73)

Kopparberg [1]

14,651

13

age 40-49

0.72
(0.38-1.37)

Edinburgh [8]

11,371

14

age 40-49

0.78
(0.46-1.32)

Meta-analyses 

Kerlikowske, et al. [9]

13 studies

7-12

age 40-49

0.92
(0.75-1.13)

U.S. Preventive Services Task Force [1]

8 studies

 

age 39-49

0.85
(0.75-0.96)

Cochrane Collaboration [10]

8 studies

13

age <50

0.84
(0.73-0.96)*

 *The combined relative risk for the three studies with good methodology was 0.87 (0.73-1.03). 
 

References  

  1. Nelson HD, Tyne K, Naik A, Bougatsos C, Chan BK, Humphrey L for the U.S. Preventive Services Task Force. Screening for breast cancer: an update for the U.S. Preventive Services Task Force. Ann Intern Med. 151(10):727-37, W237-42, 2009.
  2. 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.
  3. 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.
  4. Qaseem A, Snow V, Sherif K, Aronson M, Weiss KB, Owens DK for the Clinical Efficacy Assessment Subcommittee of the American College of Physicians. Screening mammography for women 40 to 49 years of age: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 146(7):511-5, 2007.
  5. Moss SM, Cuckle H, Evans A, et al. for the Trial Management Group. Effect of mammographic screening from age 40 years on breast cancer mortality at 10 years' follow-up: a randomised controlled trial. Lancet. 368(9552):2053-60, 2006.
  6. 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. 2014 Feb 11 [Epub ahead of print]. 
  7. Bjurstam N, Björneld L, Warwick J, et al. The Gothenburg Breast Screening Trial. Cancer. 97(10):2387-96, 2003.
  8. 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.
  9. Kerlikowske K, Grady D, Rubin SM, et al: Efficacy of screening mammography: A meta-analysis. JAMA 273:149-154, 1995.
  10. Gøtzsche PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database Syst Rev. (1):CD001877, 2011.

Updated 02/13/14