The Role of Genetic Testing in Patients With Breast Cancer

Importance: In the United States from 2009 to 2013, the incidence of breast cancer was the highest of any cancer and the death rate was second to that of lung cancer. Approximately 5% to 10% of breast cancers are inheritable. Observations: BRCA1 and BRCA2 germline mutations account for up to 30% of inheritable breast cancers and are the most commonly assessed mutations in patients presenting with early-onset breast cancer, triple-negative breast cancer, bilateral breast cancer, and a family history of breast cancer. Less common non-BRCA mutations have also been identified and contribute to hereditary breast cancer syndromes. Although established in BRCA mutations, indications and interpretations of genetic testing in non-BRCA mutations are not well defined. Furthermore, costs associated with genetic testing are highly variable and dependent on laboratory pricing, insurance coverage, and individual risk factors. Conclusions and Relevance: Genetic testing is a powerful tool that allows for the detection of BRCA and non-BRCA germline mutations in individuals with high risks of breast cancer, which in turn aids in the individualization of treatment. Given the magnitude of this disease, it is of great benefit for physicians, including general surgeons, to understand the indications, interpretations, and costs associated with genetic testing in patients with breast cancer. Cost is an especially important part of the genetic testing process and point of discussion with patients.