The rational clinical examination. Does this patient have breast cancer? The screening clinical breast examination: should it be done? How?

Abstract

Context: 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.

Objective: To collect evidence on the effectiveness of CBE in screening for breast cancer and information on the best technique to use.

Data sources: 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review of all reference lists, as well as contacting investigators of several published studies for clarifications and unpublished data.

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.

Data synthesis: 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 (kappa = 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.

Conclusions: 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.