Overview

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.