[HER2 status in gastric adenocarcinoma of Chinese: a multicenter study of 40 842 patients].

Objective: To investigation HER2 status in gastric adenocarcinoma of Chinese and contributing factors to the HER2 expression. Methods: HER2 status of 40 842 gastric adenocarcinomas and clinical data were retrospectively collected from 23 hospitals dated from 2013 to 2016. The association between HER2 positivity and clinicopathologic features was analyzed. Results: Of the 40 842 patients the median age was 62 years, the male female ratio was 2.6∶1.0. The rate of HER2 positivity was 8.8% (3 577/40 842). HER2 expression was related to the tissue type, tumor location, Lauren classification and tumor differentiation (P values: 0.009, 0.001, <0.01 and <0.01, respectively). Different HER2 expression status was observed between primary and recurrent tumors in 7.6% (48/635) cases. The rates of HER2 positivity ranged from 2% to 10% among different institutions. The rates of HER2 FISH amplification were dramatically different among the 23 hospitals (0-100%) with an average rate of 10% (810/8 156) in patients with HER2 IHC 2+ . Conclusions: HER2 expression is associated with clinicopathologic characteristics. HER2 re-assessment of tumor tissue and use of in situ hybridization techniques increase HER2 positivity. The current retrospective study should reflect the HER2 status in gastric adenocarcinoma of Chinese patients.目的： 分析中国人胃腺癌HER2检测阳性率、其影响因素及意义。 方法： 采用多中心回顾性研究，共收集23家单位2013—2016年胃腺癌手术及活检样本的HER2检测结果，统计实际检测的胃腺癌HER2阳性率，比较HER2表达与临床病理特征之间的关系，同时分析影响实际HER2阳性率的因素。 结果： 共收集胃腺癌HER2检测结果40 842例，中位年龄62岁，男女比例为2.6∶1.0。实际HER2阳性率为8.8%(3 577/40 842)；HER2阳性与标本类型、肿瘤部位、Lauren分型和分化程度相关(P值分别为：0.009、0.001、<0.01、<0.01)；同一患者两次检测结果比较，发现HER2表达不一致占7.6%(48/635)；各单位不同年份间HER2阳性率变化幅度在2%～10%之间；HER2免疫组织化学染色2＋病例再进行原位杂交检测比例(10%，810/8 156)不高，不同单位的原位杂交检测比例差别大(0～100%)。 结论： 中国人胃腺癌HER2表达与临床病理特征相关，两次检测和原位杂交检测比例是影响实际HER2阳性率的重要因素。该研究数据和结果可以基本反映中国人胃腺癌HER2检测的真实状态。.