The clinical breast examination (CBE) is widely recommended and practiced
as a tool for breast cancer screening; however, its effectiveness is dependent
on its precision and accuracy.
To collect evidence on the effectiveness of CBE in screening for breast
cancer and information on the best technique to use.
We searched the English-language literature using the MEDLINE database
(1966-1997) and manual review of all reference lists, as well as contacting
investigators of several published studies for clarifications and unpublished
Study Selection and Data Extraction
To study CBE effectiveness, we included all controlled trials and case-control
studies in which CBE was at least part of the screening modality; for technique,
we included both clinical studies and those that used silicone breast models.
All 3 authors reviewed and agreed on the studies selected for inclusion in
the pooled analyses.
Randomized clinical trials demonstrated reduced breast cancer mortality
rates among women screened by both CBE and mammography. Evidence of CBE's
independent contribution was less direct; CBE alone detected between 3% and
45%of breast cancers found that screening mammography missed. The precision
of CBE was difficult to determine because of the lack of consistent and standardized
examination techniques. Studies on CBE precision reported fair agreement (κ=0.22-0.59).
Pooling trial data, we estimated CBE sensitivity at 54% and specificity at
94%. The likelihood ratio of a positive CBE result is 10.6 (95% confidence
interval [CI], 5.8-19.2), while the likelihood ratio of a negative test result
is 0.47 (95% CI, 0.40-0.56). Longer duration of CBE and a higher number of
specific techniques used were associated with greater accuracy. The preferred
technique for CBE includes proper positioning of the patient, thoroughness
of search, use of a vertical-strip search pattern, proper position and movement
of the fingers, and a CBE duration of at least 3 minutes per breast. The value
of inspection is unproved. Professional and lay examiners improved their sensitivity
on silicone breast models after being taught this technique.
Indirect evidence supports the effectiveness of CBE in screening for
breast cancer. Although the screening clinical examination by itself does
not rule out disease, the high specificity of certain abnormal findings greatly
increases the probability of breast cancer.