胃混合性癌组织中HER2蛋白表达的判读要点

Expression and amplification of HER2 in mixed-type gastric carcinoma

目的:探讨胃混合性癌组织中人表皮生长因子受体2(human epidermal growth factor receptor-2,HER2)蛋白表达的判读要点.方法:采用免疫组织化学(immunohistochemical,IHC)和荧光原位杂交(fluorescence in situ hybridization,FISH)技术对277例胃混合性癌进行HER2蛋白表达的检测.结果:HER2蛋白表达阳性率41.5%(115/277),其中HER2蛋白表达3+广泛型7例、部分型12例、局灶型4例,占10.1%(28/277).HER2蛋白表达2+广泛型9例、部分型16例、局灶型6例,占13.4%(37/277).HER2蛋白表达1+广泛型11例、部分型24例、局灶型7例,占18.1%(50/277).阴性162例,占58.5%(162/277).H E R2基因扩增率为40.9%(47/115),其中H E R2蛋白表达3+者中占89.3%(25/28)、HER2蛋白2+者占45.9%(17/37)和HER2蛋白1+者占10.0%(5/50).47例HER2基因扩增阳性中除一例是胃混合性癌中的鳞状细胞癌区域扩增外,其余46例均为混合性癌中的腺癌区域扩增.结论:胃混合性癌HER2检测有很大的异质性,检测HER2蛋白阳性表达划分为广泛型、部分型和局灶型,此种划分能更好地为靶向抗肿瘤药物治疗过程中受益提供量化的参考指标.

AIM： To investigate the expression and amplification of human epidermal growth factor receptor-2（HER2） in mixed-type gastric carcinoma.METHODS： Immunohistochemistry（IHC） and fluorescence in situ hybridization（FISH） were used to detect the expression and amplification of HER2 in 277 cases of mixed-type gastric carcinoma, respectively.RESULTS： The overall expression rate of HER2 protein was 41.5%（115/277）. Strong HER2 protein expression（＋＋＋） accounted for 10.1%（28/277）, including diffuse expression in 7 cases, partial expression in 12 cases, and focal expression in 4 cases. Moderate HER2 protein expression（＋＋） accounted for 13.4%（37/277）, including diffuse expression in 9 cases, partial expression in 16 cases, and focal expression in 6 cases. Weak HER2 protein expression（＋） accounted for 18.1%（50/277）, including diffuse expression in 11 cases, partial expression in 24 cases, and focal expression in 7 cases. Negative HER2 protein expression was noted in 162 cases, which accounted for 58.5%（162/277）. The overall rate of HER2 gene amplification was 40.9%（47/115）, including 89.3%（25/28） of cases with strong HER2 protein expression, 45.9%（17/37） of cases with moderate HER2 protein expression and 10%（5/50） of cases with weak HER2 protein expression. Of the 47 cases with amplification of the HER2 gene, only one case occurred in the region of squamous cell carcinoma, and the remaining 46 cases occurred in the adenocarcinoma region.CONCLUSION： HER2 expression has great heterogeneity in mixed-type gastric carcinoma, and the classification of positive HER2 protein expression into diffuse, partial and focal types can provide a better quantitative parameter for targeted therapy with anti-tumor drugs.