全自动免疫组织化学和荧光原位杂交检测乳腺癌HER2状态

Analysis of HER2 status in breast carcinoma using fully automated HER2 staining and fluorescence in-situ hybridization technology

目的应用免疫组织化学和荧光原位杂交（FISH）技术检测乳腺癌组织的HER2基因状态，比较蛋白表达和基因扩增的符合率，并对乳腺癌HER2检测相关流程的优化实践进行探讨。方法依据2007年美国临床肿瘤学会／美国病理医师学院（ASCO／CAP）联合发布的乳腺癌HER2检测指南及我国2009年版乳腺癌HER2检测指南，对本院病理科在2009年5月至2011年4月期间的乳腺癌单纯手术切除标本的HER2状态检测结果进行总结分析。应用抗HER2新型抗体（兔抗人HER2单克隆抗体485）及全自动免疫组织化学检测乳腺癌中HER2蛋白表达情况，并应用FISH对其中740例标本的HER2基因扩增状态进行检测。结果2420例标本的免疫组织化学染色结果：551例（22．8％）HER2蛋白表达阳性（3＋）；664例（27．4％）不确定（2＋）；1205例（49．8％）为阴性（1＋／0）。其中740例同期进行了FISH检测：HER2蛋白表达阳性（3＋）的247例中有242例FISH结果为HER2基因扩增，阳性符合率为98．0％（242／247），1例（1／247，0．4％）为HER2基因扩增不确定；HER2蛋白表达不确定（2十）的389例中有53例（13．6％）FISH结果为HER2基因扩增，5例（1．3％）FISH结果为HER2基因扩增不确定；HER2蛋白表达阴性（1＋／0）的104例中FISH结果均为HER2基因无扩增，阴性符合率为100．0％。免疫组织化学结果为HER2阳性（3＋）和阴性（1＋／0）与FISH阳性和阴性的总体符合率为98．6％[（242＋104）／（247＋104）]。结论应用新型抗HER2抗体485联合全自动免疫组织化学和FISH检测，HER2阳性和阴性的符合率都很高，提示免疫组织化学检测为阴性和阳性结果可直接作为乳腺癌相关治疗选择的可靠依据。

Objective To determine human epidermal growth factor receptor 2 （HER2） status in breast carcinoma by the techniques of a fully automated immunohistochemistry （IHC） and fluorescence in situ hybridization （FISH） , to compare the concordance of protein expression with gene amplification and to explore the optimization in process quality control. Methods A prospective study of invasive breast cancer specimens excised between May 2009 and April 2011 at the Cancer Hospital, Chinese Academy of Medical Sciences was conducted by automated IHC staining with the new 4B5 rabbit monoclonal antibody and FISH. An evaluation was performed according to the ASCO/CAP guidelines （2007） and Chinese guidelines （2009）. The gene amplification status of 740 cases were detected by FISH. Results A total of 2420 cases of breast invasive ductal carcinoma without pre-operation therapy were tested by automated IHC. 551 cases （22. 8% ） were scored as positive （3 ＋ ）, 664 cases （27. 4% ） as equivocal （2 ＋ ）, and 1205 cases （49. 8% ） as negative （1 ＋/0）. Gene amplification was detected in 98.0% （242/247） HER2 protein expression positive （3 ＋ ） cases and in 13.6% （53/389） equivocal （2 ＋ ） cases. One of 247 （0. 4% ） HER2 expression 3 ＋ cases and 5 of 389 （ 1.3% ） HER2 expression 2 ＋ cases were equivocal for gene amplification. No gene amplification was detected in expression negative （1 ＋/0） cases by FISH （0/104）. The overall concordance between IHC and FISH was 98.6% [ （242 ＋ 104）/（247 ＋ 104） ]. Conclusions There is a high concordance rate between automated 1HC with 4B5 rabbit monoclonal antibody and FISH results for assessing the HER2 gene amplification status in surgically-excised breast cancer specimens, suggesting that automated IHC with 4B5 antibody can provide a reliable method to detect HER2 overexpression for eligibility of HER2 targeted therapy.