Powell William C, Hicks David G, Prescott Nichole, Tarr Shannon M, Laniauskas Simas, Williams Tristin, Short Sarah, Pettay James, Nagle Raymond B, Dabbs David J, Scott Katherine M, Brown Richard W, Grogan Thomas, Roche Patrick C, Tubbs Raymond R
Ventana Medical Systems Inc,; Tucson, AZ, USA.
Appl Immunohistochem Mol Morphol. 2007 Mar;15(1):94-102. doi: 10.1097/pai.0b013e31802ced25.
The 2 methodologies in current clinical use to assess HER2 status in breast cancer are: fluorescence in situ hybridization (FISH) (gene amplification) and immunohistochemistry (protein over-expression). A consistent finding has been that 3% to 15% of breast cancers over-express HER2 protein without evidence for gene amplification. Accurate determination of the HER2 status has implications for selecting patients most likely to respond to trastuzumab. We report here our preliminary experience with a new anti-HER2 rabbit monoclonal antibody, 4B5. The evaluation of HER2 status in 2 different cohorts of breast cancer cases (Single Institution (SI) and Multinational (MN)) with a total of 322 breast cancer cases was performed on an automated staining system (Ventana Medical Systems, Inc, Tucson, AZ) and scored by 3 pathologists (0-3+), for comparison with CB11 staining results (PATHWAY) and FISH (PathVysion). Interlaboratory reproducibility of automated staining results and interpretation was determined on a subset of the SI cohort at 3 separate laboratories. Rabbit monoclonal 4B5 demonstrated sharper membrane staining with less cytoplasmic and stromal background staining than CB11. In the SI cohort, the staining results for 4B5 were highly comparable with those obtained for CB11 with an overall concordance of 93.3%. In the multinational cohort, the overall concordance with CB11 was 84.7%. This lower level of concordance was associated with a much higher overall agreement of 4B5 with FISH (89.5%), compared with agreement of CB11 with FISH (81.2%). The difference in the performance of CB11 in the MN cohort versus the SI cohort may be due to differences in tissue fixation and processing in a centralized, high volume laboratory in an academic medical center versus multiple sites in the international community with potentially nonstandardized techniques. The staining results with 4B5 indicate that it has a more robust performance than CB11 because the correlation of 4B5 with FISH was nearly equivalent (88.2% MN; 89.3% SI) in both cohorts. Interlaboratory reproducibility was also excellent (kappa 1.0). RMoAb 4B5 provides excellent sensitivity, specificity, and interlaboratory reproducibility for the detection of HER2 status in breast cancer.
目前临床上用于评估乳腺癌中HER2状态的两种方法是：荧光原位杂交（FISH）（基因扩增）和免疫组织化学（蛋白过表达）。一个一致的发现是，3%至15%的乳腺癌过表达HER2蛋白，但无基因扩增证据。准确确定HER2状态对于选择最可能对曲妥珠单抗有反应的患者具有重要意义。我们在此报告我们使用一种新型抗HER2兔单克隆抗体4B5的初步经验。在一个自动染色系统（Ventana Medical Systems，Inc，图森，亚利桑那州）上对2个不同队列（单机构（SI）和多国（MN））共322例乳腺癌病例的HER2状态进行评估，并由3名病理学家评分（0-3+），以与CB11染色结果（PATHWAY）和FISH（PathVysion）进行比较。在3个不同实验室对SI队列的一个子集进行自动染色结果和解读的实验室间再现性测定。兔单克隆抗体4B5显示出比CB11更清晰的膜染色，细胞质和基质背景染色更少。在SI队列中，4B5的染色结果与CB11的染色结果高度可比，总体一致性为93.3%。在多国队列中，与CB11的总体一致性为84.7%。与CB11与FISH的一致性（81.2%）相比，这种较低水平的一致性与4B5与FISH的总体一致性更高（89.5%）相关。MN队列与SI队列中CB11性能的差异可能是由于学术医学中心集中的高容量实验室与国际社会多个可能采用非标准化技术的地点在组织固定和处理方面的差异。4B5的染色结果表明，它比CB11具有更强的性能，因为在两个队列中4B5与FISH的相关性几乎相同（MN队列中为88.2%；SI队列中为89.3%）。实验室间再现性也非常好（kappa值为1.0）。兔单克隆抗体4B5在检测乳腺癌HER2状态方面具有出色的敏感性、特异性和实验室间再现性。
