Re: A New Rabbit. Monoclonal Antibody (4B5) for the Immunohistochemical (IHC) Determination of the HER2 Status in Breast Cancer: Comparison With CB11, Fluorescence In Situ Hybridization (FISH), and Interlaboratory Reproducibility

摘要

We have read the original paper of Powell et al titled "A new rabbit monoclonal antibody (4B5) for the immunohistochemical (IHC) determination of the HER2 status in breast cancer: comparison with CB11, fluorescence in situ hybridization (FISH), and interlaboratory reproducibility" recently published in the Applied Immunohistochemistry and Molecular Morphology with great interest. They compared IHC staining for HER2 using the novel rabbit monoclonal antibody (RMoAb) 4B5 with Pathway CB11 and FISH in 2 different cohorts of breast cancer cases (SI and MN) in a total number of 322 cases and found that, however, in the SI cohort the staining results of CB11 and 4B5 were highly comparable and in the MN cohort the overall concordance was only 84.7%, associated with a much higher level of agreement of 4B5 with FISH compared with the agreement of CB11 (89.5% vs. 81.2%, respectively). The authors assume that 4B5 provides excellent sensitivity, specificity and interlaboratory reproducibility for the detection of HER2 status in breast cancer. Having read the article we are pleased to see that RMoAb 4B5 performed convincingly; however, at certain points our experi-ences with this antibody seem to differ from what the authors wrote, therefore' we would like to add a short comment to the article.