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Breast Cancer Health Center

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Breast Cancer Screening (PDQ®): Screening - Health Professional Information [NCI] - Overview


For all these potential harms of screening mammography, internal validity, consistency and external validity are good.

Clinical Breast Examination


Clinical breast examination (CBE) has not been tested independently; it was used in conjunction with mammography in one Canadian trial, and was the comparator modality versus mammography in another trial. Thus, it is not possible to assess the efficacy of CBE as a screening modality when it is used alone versus usual care (no screening activity).

Magnitude of Effect: The current evidence is insufficient to assess the additional benefits and harms of CBE. The single RCT comparing high-quality CBE to screening mammography showed equivalent benefit for both modalities. Accuracy in the community setting might be lower than in the RCT.
Study Design: Single RCT, population cohort studies.
Internal Validity: Good.
Consistency and External Validity: Poor.


Screening by CBE may lead to the following harms:

  • False-Positives with Additional Testing and Anxiety.
    Magnitude of effect: Specificity in women aged 50 to 59 years was 88% to 99%, yielding a false-positive rate of 1% to 12%.[18]
    Study Design: Descriptive population-based.
    Internal Validity, Consistency and External Validity: Good.
  • False-Negatives with Potential False Reassurance and Delay in Cancer Diagnosis.
    Magnitude of Effect: Of women with cancer, 17% to 43% have a negative CBE. Sensitivity is higher with longer duration and higher quality of the examination by trained personnel.
    Study Design: Descriptive population-based.
    Internal and External Validity: Good.
    Consistency: Fair.

Breast Self-examination


Breast self-examination (BSE) has been compared to usual care (no screening activity) and has not been shown to reduce breast cancer mortality.

Magnitude of Effect: No effect.[19,20]
Study Design: Two RCTs.
Internal Validity and Consistency: Fair.
External Validity: Poor.


Based on solid evidence, formal instruction and encouragement to perform BSE leads to more breast biopsies and diagnosis of more benign breast lesions.

Magnitude of Effects on Health Outcomes: Biopsy rate was 1.8% among the study population compared with 1.0% among the control group.[19]
Study Design: Two RCTs, cohort studies.
Internal Validity: Good.
Consistency: Fair.
External Validity: Poor.


  1. Nelson HD, Tyne K, Naik A, et al.: 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. Moss SM, Cuckle H, Evans A, et al.: 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.
  3. Miller AB, Wall C, Baines CJ, et al.: Twenty five year follow-up for breast cancer incidence and mortality of the Canadian National Breast Screening Study: randomised screening trial. BMJ 348: g366, 2014.
  4. Yen MF, Tabár L, Vitak B, et al.: Quantifying the potential problem of overdiagnosis of ductal carcinoma in situ in breast cancer screening. Eur J Cancer 39 (12): 1746-54, 2003.
  5. Welch HG, Black WC: Overdiagnosis in cancer. J Natl Cancer Inst 102 (9): 605-13, 2010.
  6. 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.
  7. Bleyer A, Welch HG: Effect of three decades of screening mammography on breast-cancer incidence. N Engl J Med 367 (21): 1998-2005, 2012.
  8. Kalager M, Zelen M, Langmark F, et al.: Effect of screening mammography on breast-cancer mortality in Norway. N Engl J Med 363 (13): 1203-10, 2010.
  9. Jørgensen KJ, Gøtzsche PC: Overdiagnosis in publicly organised mammography screening programmes: systematic review of incidence trends. BMJ 339: b2587, 2009.
  10. Rosenberg RD, Yankaskas BC, Abraham LA, et al.: Performance benchmarks for screening mammography. Radiology 241 (1): 55-66, 2006.
  11. 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.
  12. Hubbard RA, Kerlikowske K, Flowers CI, et al.: Cumulative probability of false-positive recall or biopsy recommendation after 10 years of screening mammography: a cohort study. Ann Intern Med 155 (8): 481-92, 2011.
  13. Rosenberg RD, Hunt WC, Williamson MR, et al.: Effects of age, breast density, ethnicity, and estrogen replacement therapy on screening mammographic sensitivity and cancer stage at diagnosis: review of 183,134 screening mammograms in Albuquerque, New Mexico. Radiology 209 (2): 511-8, 1998.
  14. Kerlikowske K, Grady D, Barclay J, et al.: Likelihood ratios for modern screening mammography. Risk of breast cancer based on age and mammographic interpretation. JAMA 276 (1): 39-43, 1996.
  15. Porter PL, El-Bastawissi AY, Mandelson MT, et al.: Breast tumor characteristics as predictors of mammographic detection: comparison of interval- and screen-detected cancers. J Natl Cancer Inst 91 (23): 2020-8, 1999.
  16. Ronckers CM, Erdmann CA, Land CE: Radiation and breast cancer: a review of current evidence. Breast Cancer Res 7 (1): 21-32, 2005.
  17. Goss PE, Sierra S: Current perspectives on radiation-induced breast cancer. J Clin Oncol 16 (1): 338-47, 1998.
  18. Fenton JJ, Rolnick SJ, Harris EL, et al.: Specificity of clinical breast examination in community practice. J Gen Intern Med 22 (3): 332-7, 2007.
  19. Thomas DB, Gao DL, Ray RM, et al.: Randomized trial of breast self-examination in Shanghai: final results. J Natl Cancer Inst 94 (19): 1445-57, 2002.
  20. Semiglazov VF, Manikhas AG, Moiseenko VM, et al.: [Results of a prospective randomized investigation [Russia (St.Petersburg)/WHO] to evaluate the significance of self-examination for the early detection of breast cancer]. Vopr Onkol 49 (4): 434-41, 2003.

This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

WebMD Public Information from the National Cancer Institute

Last Updated: 8/, 015
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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