Few data exist on the outcomes of interventions to reduce risk in people with a genetic susceptibility to breast or ovarian cancer. As a result, recommendations for management are primarily based on expert opinion.[1,2,3,4,5] In addition, as outlined in other sections of this summary, uncertainty is often considerable regarding the level of cancer risk associated with a positive family history or genetic test. In this setting, personal preferences are likely to be an important factor in patients' decisions about risk reduction strategies.
Screening and Prevention Strategies
Refer to the PDQ summary on Breast Cancer Screening for information on screening in the general population, and to the PDQ summary Levels of Evidence for Cancer Genetics Studies for information on levels of evidence related to screening and prevention.
In the general population, evidence for the value of breast self-examination (BSE) is limited. Preliminary results have been reported from a randomized study of BSE being conducted in Shanghai, China. At 5 years, no reduction in breast cancer mortality was seen in the BSE group compared with the control group of women, nor was a substantive stage shift seen in breast cancers that were diagnosed. (Refer to the PDQ summary on Breast Cancer Screening for more information.)
Little direct prospective evidence exists regarding BSE in individuals with an increased risk of breast cancer. In the Canadian National Breast Screening Study, women with first-degree relatives with breast cancer had statistically significantly higher BSE competency scores than those without a family history. In a study of 251 high-risk women at a referral center, five breast cancers were detected by self-examination less than a year after a previous screen (as compared with one cancer detected by clinician exam and 11 cancers detected as a result of mammography). Women in the cohort were instructed in self-examination, but it is not stated whether the interval cancers were detected as a result of planned self-examination or incidental discovery of breast masses. In another series of BRCA1/BRCA2 mutation carriers, four of nine incident cancers were diagnosed as palpable masses after a reportedly normal mammogram, further suggesting the potential value of self-examination. A task force convened by the Cancer Genetics Studies Consortium has recommended "monthly self-examination beginning early in adult life (e.g., by age 18-21 years) to establish a regular habit and allow familiarity with the normal characteristics of breast tissue. Education and instruction in self-examination are recommended."
Level of evidence: 5
Clinical breast examination
Few prospective data exist regarding clinical breast examination (CBE).
The Cancer Genetics Studies Consortium task force concluded, "as with self-examination, the contribution of clinical examination may be particularly important for women at inherited risk of early breast cancer." They recommended that female carriers of a BRCA1 or BRCA2 high-risk mutation undergo annual or semiannual clinical examinations beginning at age 25 to 35 years.