Clinical Breast Examination
No randomized trials of clinical breast examination (CBE) as a sole screening modality have been done. The Canadian National Breast Screening Study compared CBE plus mammography to CBE alone in women aged 50 to 59 years (refer to the Effect of Screening on Breast Cancer Mortality section of this summary for more information). CBE was conducted by trained health professionals with periodic evaluations of performance quality. The frequency of cancer diagnosis, stage, interval cancers, and breast cancer mortality were similar in the two groups and compared favorably with other trials of mammography alone. One explanation for this finding was the careful training and supervision of the health professionals performing CBE. Breast cancer mortality with follow-up 11 to 16 years after entry (mean = 13 years) was similar in the two screening arms (mortality rate ratio, 1.02 [95% CI, 0.78-1.33]). The investigators estimated the operating characteristics for CBE alone. For 19,965 women aged 50 to 59 years, sensitivity was 83%, 71%, 57%, 83%, and 77% for years 1, 2, 3, 4, and 5 of the trial, respectively, and specificity ranged between 88% and 96%. PPV, which is the proportion of cancers detected per abnormal examination was estimated to be 3% to 4%. For 25,620 women aged 40 to 49 years, who were examined only at entry, the estimated sensitivity was 71%, specificity 84%, and PPV 1.5%. Among community clinicians, screening CBE has higher specificity (97%-99%)  and lower sensitivity (22%-36%) compared with examiners in clinical trials of breast cancer screening.[60,61,62,63] A study of screening in women with a positive family history of breast cancer showed that, after a normal initial evaluation, the patient or CBE identified more cancers than did mammography. Another study examined the usefulness of adding CBE to screening mammography. Among 61,688 women older than 40 years and screened by mammography and CBE, sensitivity and specificity for mammography and for combined mammography-CBE were calculated. Specificity for mammography was 78% and for both modalities 82%. The increased sensitivity was greatest for women aged 60 to 69 years with dense breasts (6.8%), compared with women aged 60 to 69 years with fatty breasts (1.8%). Specificity was lower for women undergoing both screening modalities compared with mammography alone (97% vs. 99%). The duration of examination in the trials was 5 to 10 minutes per breast.
Monthly breast self-examination (BSE) is frequently advocated, but evidence for its effectiveness is weak.[66,67] The only large, well-conducted, randomized clinical trial of BSE that has been completed, randomly assigned 266,064 women according to workplace in Shanghai to receive either BSE instruction, reinforcement and encouragement, or instruction on the prevention of lower back pain. Neither group received breast cancer screening through other modalities. After 10 to 11 years of follow-up, 135 breast cancer deaths occurred in the instruction group and 131 in the control group (relative risk [RR] = 1.04; 95% CI, 0.82-1.33). Although the number of invasive breast cancers diagnosed in the two groups was about the same, women in the instruction group had more breast biopsies and more benign lesions diagnosed than did women in the control group.