Reply to Hanna et al.

In reply: The ASCO-CAP Guidelines were generated in an attempt to optimize the accuracy of HER2 testing in breast cancer and to address the documented high levels of discordance between HER2 testing reported in the literature. Indeed, the identification of methods that can be employed to ensure the accuracy of HER2 testing was also the motivation of the study of HER2 IHC and FISH concordance that we have reported in this issue of Modern Pathology. Furthermore, one of the authors of our study (AG) was present at the ad hoc committee meeting that preceded the generation of the published guidelines.1