Laboratory Compliance with the American Society of Clinical Oncology/College of American Pathologists Guidelines for Human Epidermal Growth Factor Receptor 2 Testing: A College of American Pathologists Survey of 757 Laboratories (Cap Laboratory Improvement Programs‪)‬

Human epidermal growth receptor 2 gene ERBB2 (commonly referred to as HER2) amplification status is an important prognostic marker in breast cancer and is a factor in determining patient therapy. (1-5) The American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) introduced guidelines for HER2 testing in December 2006, which were subsequently published in January 2007. (6) These guidelines were produced in response to studies that indicated that up to 20% of HER2 results may be discordant with another laboratory. (7,8) The ASCO/CAP publications identified possible sources of variations and gave guideline recommendations to promote test standardization in the hope of For editorial comment, see p 660. improving test accuracy and patient safety. This was coupled with efforts by the Laboratory Accreditation Program (LAP) of the CAP to strengthen its accreditation standards regarding immunohistochemistry (IHC) in general and HER2 testing specifically. (9) As of January 2008, the LAP mandates that laboratories be in compliance with the ASCO/CAP guidelines. In an effort to understand the effect of these guidelines on laboratories, pathologists and staff involved in the CAP proficiency testing program conducted a survey to identify areas in which laboratories may be having difficulty successfully implementing the guideline recommendations. MATERIALS AND METHODS