Precision medicine for breast cancer is an approach to diagnosis, treatment and prevention that takes into account the genes you're born with (your genetic makeup) and the genes or others markers present within the cancer cells. With this approach, your blood or tumor tissue is collected for analysis, often genetic. The information may help predict or diagnose disease and guide treatment decisions.
Cancer care is among the first medical specialties to apply precision medicine. Several kinds of genetic and nongenetic tests for breast cancer are available that can help personalize therapy. Some genetic tests are specific to inherited risk, which means they look at your genetic makeup to determine your personal risk of developing breast cancer or other types of cancer in your lifetime. Inherited risk accounts for about 10 percent of all breast cancer cases.
Other tests check for genetic changes or variants (sometimes called mutations) within the cancer cells that help determine which treatments you'll most likely benefit from or if you need any treatments at all. For example, cells from a breast tumor may be tested to determine whether they produce too much of a protein called HER2. Someone with HER2-positive breast cancer is likely to respond to the drugs that target that protein. Some genetic tests will reveal whether your body will turn on (activate) certain medications thus helping to determine which treatment may be best for you.
Eventually, with new advances in precision medicine (also called individualized or personalized medicine) many more precise choices will become available.
Precision medicine for breast cancer at Mayo Clinic
Why it's done
Your doctor may talk with you about a clinical trial for a new breast cancer drug.
The goal of precision medicine for breast cancer is to tailor treatment to your particular genetic makeup and the genetic changes in the cancer cells.
Precision medicine for breast cancer may involve analyzing the genetic makeup of your cells or, if you have cancer, the makeup of your cancer cells. Tests might include:
- Drug-gene testing. Your genes may influence the way your body processes medications, including those used to treat breast cancer. Your doctor may use information from a genetic test of your cells to determine which medications and dosages are most appropriate for you. The field of drug-gene interactions is called pharmacogenomics.
- Advanced cancer. If your cancer progresses despite treatment, your doctor might recommend testing the genetic makeup of your cancer cells. This test, called tumor sequencing, is used to look for changes or alterations in the cancer so that your doctor can choose the best drug for your type of tumor.
- Family history. Genetic testing for inherited gene mutations that increase your risk of breast cancer, such as the BRCA gene, is offered to people with a strong family history of the disease. Women who have these genes have an increased risk of developing breast cancer compared with the general population. This same test can also be used to determine if you would respond to a specific drug for the treatment of metastatic breast cancer (Parp inhibitor). Other, newer genetic tests may be available, too, depending on a person's family cancer history.
Precision medicine for breast cancer care at Mayo Clinic
Dec. 23, 2017
- Alisertib with or without fulvestrant in treating patients with locally advanced or metastatic, endocrine-resistant breast cancer. https://clinicaltrials.gov/ct2/show/NCT02860000. Accessed Sept. 9, 2017.
- BRCA1 and BRCA2: Cancer risk and genetic testing. National Cancer Institute. http://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet. Accessed June 13, 2017.
- Luo K, et al. A phosphorylation-deubiquitination cascade regulates the BRCA2-RAD51 axis in homologous recombination. Genes & Development. 2016;30:1.
- Van Poznak C, et al. Use of biomarkers to guide decisions on systemic therapy for women with metastatic breast cancer: American Society of Clinical Oncology Clinical Practice Guideline. Journal of Oncology Practice. 2015;11:514.
- Goetz MP (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 26, 2017.
- Gradishar WJ, et al. Invasive breast cancer version 1.2016. Clinical practice guidelines in oncology. Journal of the National Comprehensive Cancer Network. 2016;14:324.
- Studying genes. National Institute of General Medical Sciences. https://www.nigms.nih.gov/Education/pages/Factsheet_studyinggenes.aspx. Accessed June 13, 2017.
- AskMayoExpert. Genetic testing for BRCA1 and BRCA2 mutations. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2017.
- Mayo Clinic to be home of National Precision Medicine Initiative (PMI) Cohort Program Biobank. News release, Mayo Clinic, Rochester, Minnesota. Sept. 26, 2017.
- AskMayoExpert. Breast cancer. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.
- Goetz MP, et al. Tumor sequencing and patient-derived xenografts in the neoadjuvant treatment of breast cancer. Journal of the National Cancer Institute. 2017;109:djw306. Accessed June 12, 2017.
- Couch FJ, et al. Associations between cancer predisposition testing panel genes and breast cancer. JAMA Oncology. 2017;3:1190.
- Hamburg MA, et al. The path to personalized medicine. New England Journal of Medicine. 2010;363:301.
- Electronic Medical Records and Genomics (eMERGE) Network. National Human Genome Research Institute. https://www.genome.gov/27540473/electronic-medical-records-and-genomics-emerge-network/#al-2. Accessed June 12, 2017.
- Pritchard DE, et al. Strategies for integrating personalized medicine into healthcare practice. Personalized Medicine. 2017;14:141.
- The Personalized Medicine Coalition. Personalized Medicine at FDA: 2016 Progress Report. http://www.personalizedmedicinecoalition.org/Resources/Personalized_Medicine_at_FDA. Accessed June 13, 2017.
- Peshkin BN. Genetic counseling and testing for hereditary breast and ovarian cancer. http://www.uptodate.com/contents/search. Accessed June 13, 2017.
- Raby BA. Personalized medicine. https://www.uptodate.com/contents/search. Accessed June 13, 2017.
- Liu T, et al. CDK4/6-dependent activation of DUB3 regulates cancer metastasis through SNAIL1. Nature Communication. 2017;8:13923.
- Ingle JN, et al. Genetic polymorphisms in the long noncoding RNA MIR2052HG offer a pharmacogenomics basis for the response of breast cancer patients to aromatase inhibitor therapy. Cancer Research. 2016;76:7012.
- Ingle JN, et al. Estrogens and their precursors in postmenopausal women with early breast cancer receiving anastrozole. Steroids. 2015;99:32.
- Goetz MP, et al. CYP2D6 metabolism and patient outcome in the Austrian Breast and Colorectal Cancer Study Group trial (ABCSG) 8. Clinical Cancer Research. 2013;19:500.
- Goetz MP, et al. First-in-human phase I study of the tamoxifen metabolite Z-endoxifen in women with endocrine-refractory metastatic breast cancer. Journal of Clinical Oncology. In press. Accessed Oct. 17, 2017.
- D'Assoro AB, et al. The mitotic kinase Aurora-A promotes distant metastases by inducing epithelial-to-mesenchymal transition in Era(+) breast cancer cells. Oncogene. 2014;33:599.
Precision medicine for breast cancer