There are several methods of screening – self breast examination (SBE), clinical breast examination (CBE) (by doctor or health worker), and mammography. None of these methods, except mammography, has been shown by randomized, controlled trials (RCTs) to be an effective tool for early detection. Combinations of these and newer methods such as ultrasound and computed tomography (CT) scanning are also used.
Women who used self-breast examination did not find smaller or more curable tumors than those who did not. In fact, there were significantly more biopsies that proved negative in women who used self-breast examination. Studies have found that tumors found in those women who used self-breast examination were similar in size to those found in women who did not use self-breast examination. Thus, there is no good evidence of benefit, and evidence of harm, in teaching self-breast examination to women of all ages.
Clinical breast examination
The efficacy of clinical breast examination is dependent on the amount of time the provider spends. Its sensitivity has been estimated at 54%, with a specificity of 94%. In women aged 50-59 years, one large randomized, controlled trials found that clinical breast examination alone was as effective as mammography, although mammography was more sensitive in detecting small cancers.
Mammography has been recommended as the most efficient method of screening in women over age 50 years. The Health Insurance Plan Breast Cancer Screening Project completed in 1963 after it had followed more than 60 000 women aged 40-64 for more than ten years was the first study to find that women in the screening group had a 30% reduction in breast cancer mortality. Six of seven subsequent large randomized, controlled trials that differed somewhat in methods found significant reduction in mortality rates in those women who were screened with mammography.
Ultrasonography has been the radiologic examination of choice in evaluation of breast lumps and abnormalities in younger women, especially those under 25 years. Used with mammography, especially in women with dense breasts, ultrasound significantly increase the detection of small cancers and those at smaller size and lower stage.
- Lawson, H. Henson, R., Bobo, J.K. and Kaesar, M.K. Implementing recommendations for the early detection of breast and cervical cancer among low income women. Morb. Mortal. Weekly Report. 2000
- Blamey, R. W., Wilson, A. R. M. and Patnick, J. ABC of breast diseases: screening for breast cancer. Br. Med. J. 2000.