> Table 31: Digital mammography versus film mammography for breast cancer screening
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.
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Introduction: A mammogram is an X-ray image of the breast. The images can be captured on film or stored directly onto a computer (digital). Because digital mammogram images are stored on a computer, they can be lightened or darkened, and certain sections can be enlarged and examined more closely.
Film and digital mammography are similar in their ability to find cancer [1-3]. However, the ability to control images on a computer makes digital mammography a more accurate screening tool for some women. In general, digital mammography is better at finding cancer in women who fall into one or more of the following groups [2]:
- Women who are premenopausal or peri-menopausal
- Women who are under age 50
- Women who have dense breast tissue
Women who are young and those who are pre- or peri-menopausal tend to have dense breast tissue, so these groups overlap.
For women who do not fall in one of the above groups, film and digital mammography are similar in their ability to find breast cancer early.
Learn more about film and digital mammography.
Study measures (sensitivity and specificity)
The main goal of any cancer screening test is to correctly identify those people who have cancer (called the sensitivity of the test). When sensitivity is high, very few cases are missed. However, this means some healthy people will be misidentified as having cancer (a false positive result). For example, a sensitivity of 90 percent means that 90 percent of people tested who truly have cancer are correctly identified as having cancer.
An ideal cancer screening test would also be able to correctly identify all the people who do not have cancer as not having it (called the specificity of the test). When specificity is high, there are fewer false positive results, but more cases of true cancer are missed. For example, a specificity of 90 percent means that 90 percent of the people who are healthy are correctly identified as not having cancer.
No screening test has perfect sensitivity and perfect specificity. There is a trade-off between the two for all types of screening tests. That is, when a test gains sensitivity, it loses some specificity.
Learn more about the quality of screening tests.
Study selection criteria: Clinical trials that included at least 1,000 mammograms.
Table note: The studies presented below compare quality measures for screening (sensitivity and specificity) with film and digital mammography. At this time, there are no data comparing survival for women who have film mammography versus those who have screening with digital mammography.
Study
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Study Population
(number of participants)
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Sensitivity
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Specificity
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Film Mammography
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Digital Mammography
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Film Mammography
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Digital Mammography
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Randomized clinical trials
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Skaane et al. (Oslo II Study) [1]
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23,929
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61.5%NS
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77.4%NS
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97.9%SIG
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96.5%SIG
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Clinical trials
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Pisano et al. (DMIST) [2,3]
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42,760
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66%NS
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70%NS
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92%NS
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92%NS
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Among women <50 years old with dense breast tissue
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27%SIG
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59%SIG
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89%NS
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90%NS
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Among women <50 years old with non-dense breast tissue
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NS
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NS
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NS
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NS
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Among women 50 years or older with dense breast tissue
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NS
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NS
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NS
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NS
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Among women 50 years or older with non-dense breast tissue
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NS
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NS
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NS
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NS
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Lewin et al. [4]
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4,945
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63%NS
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60%NS
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N/A
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N/A
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NS = No statistically significant difference in diagnostic accuracy between film mammography and digital mammography.
SIG = Statistically significant difference in diagnostic accuracy between film mammography and digital mammography.
N/A = Results not available.
References
1. Skaane P, Hofvind S, Skjennald A. Randomized trial of screen-film versus full-field digital mammography with soft-copy reading in population-based screening program: follow-up and final results of Oslo II study. Radiology. 244(3):708-17, 2007.
2. Pisano ED, Gatsonis C, Hendrick E, et al. for the Digital Mammographic Imaging Screening Trial (DMIST) Investigators Group. Diagnostic performance of digital versus film mammography for breast-cancer screening. N Engl J Med. 353(17):1773-83, 2005.
3. Pisano ED, Hendrick RE, Yaffe MJ, et al. for the Digital Mammographic Imaging Screening Trial (DMIST) Investigators Group. Diagnostic accuracy of digital versus film mammography: exploratory analysis of selected population subgroups in DMIST. Radiology. 246(2):376-83, 2008.
4. Lewin JM, Hendrick RE, D'Orsi CJ, et al. Comparison of full-field digital mammography with screen-film mammography for cancer detection: results of 4,945 paired examinations. Radiology. 218(3):873-80, 2001.
Updated 04/17/13
