The value of BSE is similar to that of CBE - that is, it is a form of low-cost surveillance for breast changes that should be brought to the attention of a physician. For women younger than age 40 who are at average risk, routine BSE can heighten awareness of the normal composition of the breasts. This benefit continues after a woman begins undergoing routine mammography, although the greater advantage is the potential to be alert to a palpable mass that may have been missed by recent mammography or a lesion that is fast growing. One methodologic problem associated with the evaluation of BSE relates to whether self-detected tumors are found during BSE or at some other time. However, the more important issue is awareness of an abnormality rather than the occasion of detection (i.e., self-discovery versus BSE).
It is doubtful that new studies will provide additional insights into the value of these examinations; for this reason, the most pragmatic approach is to view these physical examinations in the context of their age-specific relevance. For women younger than age 40, when breast cancer incidence is comparatively lower, regular BSE and periodic CBE provide an opportunity to identify the emergence of a palpable mass earlier rather than later. After a woman begins having regular mammograms, CBE and BSE provide a safeguard against the limitations of mammography.
Mammography participation rates rose rapidly in the late 1980s and have continued to increase during the last decade. Among states (n = 50, plus the District of Columbia) participating in the CDC’s Behavioral Risk Factor Surveillance System, the median percentage of women age 40 and older who reported ever having had a mammogram is 84% (range, 71.8 to 91.4). The median percentage of women reporting a recent mammogram is lower and declines with increasing age. Among women aged 40 to 49, the median percentage reporting a mammogram in the past 2 years is 65.4% (range, 50.2 to 74.4). Although not directly comparable, the median proportion of women aged 50 and older who reported having had a mammogram in the past year is 57% (range, 41.8 to 70.1), and for women 65 and older, the median proportion is 54.1% (range, 38.3 to 67.7).
As noted previously in the section Principles of Cancer Screening, an important factor in planning a screening program is identifying a population with sufficient prevalence of occult disease. It would seem logical, then, that breast cancer risk factors other than age might prove useful in improving the efficiency of screening programs. This potential could extend to determining when to begin screening, which women should be screened at shorter or wider screening intervals, and, ideally, organizing screening programs on the basis of risk so that a truly low-risk population could be excluded from routine testing.
What, then, is the potential for making individual decisions about screening based on risk apart from the recommendations or guidelines issued by medical organizations? When answering these questions, it is important to distinguish between program considerations relating to cost-effectiveness and the decision reached by an individual woman based on her unique circumstances.
For women at very high risk, due to a significant family history in first-degree relatives diagnosed premenopausally, a family history suggestive of an inherited predisposition to breast cancer, or confirmation of an inherited mutation of known significance on a breast cancer susceptibility gene, more aggressive surveillance has been recommended based on expert opinion. Women with a prior diagnosis of breast cancer, DCIS, lobular neoplasia, or atypical hyperplasia might also reach a decision with their physician to establish a program of more aggressive surveillance.
For women who do not fall into these higher-risk categories, it also has been proposed that informed decisions about screening should be made weighing comparative risks (e.g., cost, inconvenience, anxiety associated with false-positive results, harm associated with avoidable biopsy) and benefits. The underlying message in this recommendation is that women should understand their risk of breast cancer, the benefit of screening, and the comparative risk of harm associated with screening.