Breast Cancer Health Center

continued...

Statement of harms

Based on solid evidence, screening by clinical breast examination may lead to the following harms:

Table 2. Harms of Screening Clinical Breast Examination

Screening by Breast Self-Examination

Statement of benefit

Based on fair evidence, teaching breast self-examination does not reduce breast cancer mortality.

Description of the Evidence

• Study Design: One RCT, case-control trials, and cohort evidence.
• Internal Validity: Good.
• Consistency: Fair.
• Magnitude of Effects on Health Outcomes: No difference in breast cancer mortality was seen after 10 years in Shanghai factory workers randomly assigned to receive breast self-examination instruction and reinforcement, compared with the control group. Forty percent of the women enrolled, however, were younger than 40 years.[15]
• External Validity: Poor.

Statement of harms

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

Description of the Evidence

• Study Design: One RCT.
• Internal Validity: Good.
• Consistency: Fair.
• Magnitude of Effects on Health Outcomes: Biopsy rate is 1.8% among the study population compared with 1.0% among the control group.[15]
• External Validity: Poor.

References:

1. Nystr�m L, Andersson I, Bjurstam N, et al.: Long-term effects of mammography screening: updated overview of the Swedish randomised trials. Lancet 359 (9310): 909-19, 2002.
2. Shapiro S: Periodic screening for breast cancer: the Health Insurance Plan project and its sequelae, 1963-1986. Baltimore, Md: Johns Hopkins University Press, 1988.
3. Miller AB, To T, Baines CJ, et al.: The Canadian National Breast Screening Study-1: breast cancer mortality after 11 to 16 years of follow-up. A randomized screening trial of mammography in women age 40 to 49 years. Ann Intern Med 137 (5 Part 1): 305-12, 2002.
4. Miller AB, Baines CJ, To T, et al.: Canadian National Breast Screening Study: 2. Breast cancer detection and death rates among women aged 50 to 59 years. CMAJ 147 (10): 1477-88, 1992.
5. 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.
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. 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.
8. 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.
9. 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.
10. 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.
11. Ronckers CM, Erdmann CA, Land CE: Radiation and breast cancer: a review of current evidence. Breast Cancer Res 7 (1): 21-32, 2005.
12. Goss PE, Sierra S: Current perspectives on radiation-induced breast cancer. J Clin Oncol 16 (1): 338-47, 1998.
13. 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.
14. Baines CJ, Miller AB, Bassett AA: Physical examination. Its role as a single screening modality in the Canadian National Breast Screening Study. Cancer 63 (9): 1816-22, 1989.
15. 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.