Breast cancer is different in each patient and therefore physicians strive to set up a treatment plan that is tailored to each patient’s individual situation. In most cases, surgical removal of the tumor is a critical step in the treatment of breast cancer. The next step can be additional therapy to minimize the chance of any remaining tumor spreading (metastasizing). In many cases it is very difficult to determine whether an individual patient has a high or low risk that her cancer will spread to other sites. MammaPrint^® is a test that provides a physician with additional information to assess the risk of breast cancer recurrence.