In this patient who has no family history of breast or ovarian cancer, no further testing is necessary, despite the results of the direct-to-consumer genetic test. Direct-to-consumer genetic testing, though attractive to patients, is fraught with many potential drawbacks, including the uncertain validity of the tests themselves. This form of testing relies on a case-control–based approach. Single-nucleotide polymorphisms (SNPs) that are disproportionately found in affected individuals with a specific disease are identified, and odds ratios indicating the influence of particular SNPs on the pretest likelihood for the disease are calculated. Unfortunately, most SNPs have very low odds ratios and contribute only a small proportion to total disease burden. This approach also does not capture the complex interaction between genetic influences on development of disease or the effect of other factors, such as environmental exposures, among other potentially confounding issues. Therefore, a positive result with this type of testing frequently does not indicate an increased probability of having the disease but may cause unnecessary patient concern and anxiety.

Additionally, given the lack of pretest counseling, an essential component of proper genetic testing in which the basic concepts of genetic testing and interpretation can be explained, patient misinterpretation of test results is especially likely. It is essential that this patient be educated about the implications of her test results, including the limitations. This patient should be informed that her risk of developing breast cancer is not 52.5% and is instead much lower. Even if the results of this test were found to be valid, her lifetime risk of developing breast cancer would increase from 12.4% (the lifetime risk for women born in the United States who are considered to be at average risk) to approximately 19%.

According to the U.S. Preventive Services Task Force (USPSTF), BRCA genetic testing should be limited to patients whose family history indicates a possible familial inheritance as seen by the presence of BRCA-related malignancies. There is no such indication of a familial pattern of disease in this patient; therefore, BRCA genetic testing would not be indicated.

Breast MRI is a highly sensitive study for detection of breast cancers and other breast pathology. However, its appropriate use as a screening tool is evolving, with variable recommendations existing for use in patients considered at high risk for breast cancer. This patient does not have a clear increased risk based on her history or the results of her direct-to-consumer genetic testing. Therefore, initiating screening MRI in this patient would not be appropriate.

Breast self-examination has not been shown to be a reliable method for detection of breast cancer in average-risk women or in those at increased risk, and the USPSTF advises against its use for screening. It would therefore not be an appropriate management recommendation for this patient.