Abstract
New testing technologies—increasingly based on genomic information—are essential in the shift toward personalized medicine and molecular targeted therapies. Considering the rapid proliferation of new tests, health care insurers and policy makers are interested in assessing evidence about their use and value. It is critical to build an evidence base to support effective decision making related to testing technologies as they are used in clinical practice. The example of human epidermal growth factor receptor 2 (HER2, or ERBB2) testing for breast cancer illustrates the challenges and opportunities. Many groups, including the Institute of Medicine, Agency for Healthcare Research and Quality, Secretary's Advisory Committee on Genetics, Health, and Society, President's Council of Advisors on Science and Technology, and Evaluation of Genomic Applications in Practice and Prevention Project, have cited the need to improve the evidence base for genomic and testing technologies. This Commentary extends previous work, emphasizing the need for evidence to assess how technologies are actually used in clinical practice.