The primary objective is to evaluate the concordance between human epidermal growth factor receptor 2 (HER2) status determined by the participating laboratory and by the centralized laboratory. HER2 status of samples was tested by the participating laboratories (investigator's choice of immunohistochemistry [IHC] and in situ hybridization [ISH] methods) and by the centralized laboratories (IHC using the 4B5 anti-HER antibody and Silver ISH). Positive HER2 status was defined as a score of IHC3+ or IHC2+/ISH+.