Genomic expression profiling of tumors is used to individualize early-stage breast cancer treatment. However, very little is known about patients' understanding of and desired information about these tests, such as Oncotype DX. We addressed these issues via a survey mailed to 130 early-stage breast cancer patients who received an Oncotype DX test result. The survey assessed understanding (14 items), information desired about genomic expression profiling tests, and if and where they sought information about Oncotype DX. Sixty-four surveys were returned. Overall, 54% of the knowledge items were answered correctly. Patients wanted education about genomic tests in many areas. Overall, 62% sought information about the test, primarily from the Internet (48%) and doctor or health care provider (31%). In sum, patients' misunderstanding of genomic tests abound, necessitating better educational efforts on behalf of health care systems to meet their needs for varied information through different communication channels.