> Table 29b: Breast cancer screening with mammography for ages 50–69
This summary table contains detailed information about research studies. While viewing summary tables offers an informative glimpse at the science behind many breast cancer guidelines and recommendations, they should be viewed with some caution. There are a number of concepts you must understand to be able to successfully read and interpret research tables. To get some background information about understanding research tables, please see How to Read a Research Table.
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Introduction: There are clear benefits to screening mammography in women ages 50-69. Not all the randomized controlled trials to date have found a strong benefit of mammography. However, when the results of studies are combined in meta-analyses, results show that mammograms in women ages 50-69 reduce breast cancer mortality.
There has been a controversy on the benefits of mammography for women of any age. In 2000, the authors of a report reviewing the trials on mammography called into question the methods of some of these studies. They concluded that the evidence pointed to mammography having no benefit [1]. However, when researchers revisited these trials in response to the report, they concluded that while there were some problems with the trials, the evidence as a whole still shows that mammography reduces mortality [2,3].
Study selection criteria: Randomized controlled trials.
Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.
Study
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Study Population
(number of participants)
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Follow-up
(years)
|
Age at Screening
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Relative Risk of Breast Cancer Mortality in Women Who Were Screened Compared to Women Who Were Not
RR (95% CI)
|
Randomized controlled trials
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Ostergotland [3]
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55,059
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13
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age 50-74
|
0.70 (0.62-0.80)
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Kopparberg [3]
|
42,558
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13
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age 50-74
|
0.55 (0.42-0.73)
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CNBSS-2 [4]
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39,405
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13
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age 50-59
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1.02 (0.78-1.33)
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Stockholm [3]
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38,318
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13
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age 50-64
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0.64 (0.41-1.01)
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Malmo I [3]
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34,856
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13
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age 50-69
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0.86 (0.64-1.16)
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Malmo II [2]
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34,229
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16.9
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age 50-70
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0.83 (0.66-1.04)
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HIP-study [2]
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33,010
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18
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age 50-64
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0.79 (0.58-1.06)
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Edinburgh [5]
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32,897
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14
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age 50-54
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1.09 (0.69-1.71)
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|
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age 55-59
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0.71 (0.47-1.07)
|
| |
|
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age 60-64
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0.87 (0.57-1.35)
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Gothenburg [6]
|
25,670
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14
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age 50-54
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1.06 (0.66-1.72)
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age 55-59
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0.67 (0.43-1.06)
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Meta-analyses
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Cochrane Collaboration [3]
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268,874
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13
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age 50+
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0.77 (0.69-0.86)*
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Kerlikowske et al. [7]
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13 studies
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7-12
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age 50-74
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0.77 (0.69-0.87)
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*The combined relative risk for the two studies deemed optimal in their methodology was 0.94 (0.77-1.15).
References
1. Gotzsche PC and Olsen O. Is screening for breast cancer with mammography justifiable? Lancet. 355: 129-134, 2000.
2. Humphrey LL, Helfand M, Chan BKS, et al. Breast cancer screening: a summary of the evidence for the U.S. Preventive Services Task Force. Annals of Internal Medicine. 137(5): 347-367, 2002.
3. Gotzshe PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database Syst Rev. 18;(4):CD001877, 2006.
4. Miller AB, To T, Baines CJ, Wall C. Canadian National Breast Screening Study-2: 13-year results of a randomized trial in women aged 50-59 years. J Natl Cancer Inst. 92(18):1490-9, 2000.
5. 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.
6. Bjurstam N, Björneld L, Warwick J, et al. The Gothenburg Breast Screening Trial. Cancer. 97(10):2387-96, 2003.
7. Kerlikowske K, Grady D, Rubin SM, et al. Efficacy of screening mammography: A meta-analysis. JAMA. 273:149-154, 1995.
Updated 11/19/09
