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Breast Cancer Screening (PDQ®): Screening - Health Professional Information [NCI] - Harms of Screening Mammography


False-Negatives Leading to Possible False Sense of Security

The sensitivity of mammography (refer to the Breast Cancer Screening Concepts section of this summary for more information) ranges from 70% to 90%, depending on a woman's age and the density of her breasts, which is affected by her genetic predisposition, hormone status, and diet. Assuming an average sensitivity of 80%, mammograms will miss approximately 20% of the breast cancers that are present at the time of screening (false-negatives). Many of these missed cancers are high risk, with adverse biologic characteristics (refer to the Interval cancers section in the Breast Cancer Screening Concepts section of this summary for more information ). If a "normal" mammogram dissuades or postpones a woman or her doctor from evaluating breast symptoms, she may suffer adverse consequences. Thus, a negative mammogram should never prevent work-up of breast symptoms.


Compression of the breast is important during a mammogram to reduce motion artifact and improve image quality. Positioning of the woman is important. One study that evaluated how often pain and discomfort are felt during mammography reported that 90% of women undergoing mammography had discomfort, and 12% rated the sensation as intense or intolerable.[18]

Radiation Exposure

The major predictors of radiation risk are young age at exposure and dose. For women older than 40 years, the benefits of annual mammograms probably outweigh the potential risk,[19] but certain subpopulations of women may have an inherited susceptibility to ionizing radiation damage. [20,21] In the United States, the mean glandular dose for screening mammography is 1 mGy to 2 mGy (100–200 mrad) per view or 2 mGy to 4 mGy (200–400 mrad) per standard two-view exam. [22,23]


Because large numbers of women have false-positive tests, the issue of psychological distress—which may be provoked by the additional testing—has been studied. A telephone survey of 308 women performed 3 months after screening mammography revealed that about one-fourth of the 68 women with a "suspicious" result were still experiencing worry that affected their mood or functioning, even though subsequent testing had ruled out a cancer diagnosis.[24] Several studies,[25,26,27] however, show that the anxiety following evaluation of a false-positive test leads to increased participation in future screening examinations.[28]


  1. Kerlikowske K, Grady D, Barclay J, et al.: Positive predictive value of screening mammography by age and family history of breast cancer. JAMA 270 (20): 2444-50, 1993.
  2. Elmore JG, Barton MB, Moceri VM, et al.: Ten-year risk of false positive screening mammograms and clinical breast examinations. N Engl J Med 338 (16): 1089-96, 1998.
  3. Christiansen CL, Wang F, Barton MB, et al.: Predicting the cumulative risk of false-positive mammograms. J Natl Cancer Inst 92 (20): 1657-66, 2000.
  4. Welch HG, Fisher ES: Diagnostic testing following screening mammography in the elderly. J Natl Cancer Inst 90 (18): 1389-92, 1998.
  5. Rosen EL, Baker JA, Soo MS: Malignant lesions initially subjected to short-term mammographic follow-up. Radiology 223 (1): 221-8, 2002.
  6. Welch HG, Black WC: Using autopsy series to estimate the disease "reservoir" for ductal carcinoma in situ of the breast: how much more breast cancer can we find? Ann Intern Med 127 (11): 1023-8, 1997.
  7. Black WC, Welch HG: Advances in diagnostic imaging and overestimations of disease prevalence and the benefits of therapy. N Engl J Med 328 (17): 1237-43, 1993.
  8. Duffy SW, Lynge E, Jonsson H, et al.: Complexities in the estimation of overdiagnosis in breast cancer screening. Br J Cancer 99 (7): 1176-8, 2008.
  9. Gøtzsche PC, Jørgensen KJ, Maehlen J, et al.: Estimation of lead time and overdiagnosis in breast cancer screening. Br J Cancer 100 (1): 219; author reply 220, 2009.
  10. Gøtzsche PC, Nielsen M: Screening for breast cancer with mammography. Cochrane Database Syst Rev (4): CD001877, 2006.
  11. Zackrisson S, Andersson I, Janzon L, et al.: Rate of over-diagnosis of breast cancer 15 years after end of Malmö mammographic screening trial: follow-up study. BMJ 332 (7543): 689-92, 2006.
  12. Hemminki K, Rawal R, Bermejo JL: Mammographic screening is dramatically changing age-incidence data for breast cancer. J Clin Oncol 22 (22): 4652-3, 2004.
  13. Jonsson H, Johansson R, Lenner P: Increased incidence of invasive breast cancer after the introduction of service screening with mammography in Sweden. Int J Cancer 117 (5): 842-7, 2005.
  14. Johnson A, Shekhdar J: Breast cancer incidence: what do the figures mean? J Eval Clin Pract 11 (1): 27-31, 2005.
  15. White E, Lee CY, Kristal AR: Evaluation of the increase in breast cancer incidence in relation to mammography use. J Natl Cancer Inst 82 (19): 1546-52, 1990.
  16. Feuer EJ, Wun LM: How much of the recent rise in breast cancer incidence can be explained by increases in mammography utilization? A dynamic population model approach. Am J Epidemiol 136 (12): 1423-36, 1992.
  17. Zahl PH, Strand BH, Maehlen J: Incidence of breast cancer in Norway and Sweden during introduction of nationwide screening: prospective cohort study. BMJ 328 (7445): 921-4, 2004.
  18. Freitas R 2nd, Fiori WF, Ramos FJ, et al.: [Discomfort and pain during mammography]. Rev Assoc Med Bras 52 (5): 333-6, 2006 Sep-Oct.
  19. Feig SA, Ehrlich SM: Estimation of radiation risk from screening mammography: recent trends and comparison with expected benefits. Radiology 174 (3 Pt 1): 638-47, 1990.
  20. Helzlsouer KJ, Harris EL, Parshad R, et al.: Familial clustering of breast cancer: possible interaction between DNA repair proficiency and radiation exposure in the development of breast cancer. Int J Cancer 64 (1): 14-7, 1995.
  21. Swift M, Morrell D, Massey RB, et al.: Incidence of cancer in 161 families affected by ataxia-telangiectasia. N Engl J Med 325 (26): 1831-6, 1991.
  22. Kopans DB: Mammography and radiation risk. In: Janower ML, Linton OW, eds.: Radiation Risk: a Primer. Reston, Va: American College of Radiology, 1996, pp 21-22.
  23. Suleiman OH, Spelic DC, McCrohan JL, et al.: Mammography in the 1990s: the United States and Canada. Radiology 210 (2): 345-51, 1999.
  24. Lerman C, Trock B, Rimer BK, et al.: Psychological side effects of breast cancer screening. Health Psychol 10 (4): 259-67, 1991.
  25. Gram IT, Lund E, Slenker SE: Quality of life following a false positive mammogram. Br J Cancer 62 (6): 1018-22, 1990.
  26. Burman ML, Taplin SH, Herta DF, et al.: Effect of false-positive mammograms on interval breast cancer screening in a health maintenance organization. Ann Intern Med 131 (1): 1-6, 1999.
  27. Pisano ED, Earp J, Schell M, et al.: Screening behavior of women after a false-positive mammogram. Radiology 208 (1): 245-9, 1998.
  28. Brewer NT, Salz T, Lillie SE: Systematic review: the long-term effects of false-positive mammograms. Ann Intern Med 146 (7): 502-10, 2007.

WebMD Public Information from the National Cancer Institute

Last Updated: February 25, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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