A comprehensive study of HER2 aberration of gastric cancers in viewing as the target of molecular therapy

对475例福尔马林固定的石蜡包埋组织进行免疫组织化学和荧光原位杂交(FISH)联合分析，对51例HER2扩增的胃腺癌组织进行检测。HER2扩增的异质性，如果定义为不到50%的癌细胞对ERBB2扩增阳性，21个肿瘤(42%)将是异质性的。多重连接依赖的探针扩增(MLPA)和FISH联合分析显示，8例肿瘤单个细胞HER2和MYC共扩增，1例MYC/FGFR2和MYC/EGFR共扩增。HER2/EGFR共扩增7例，HER2/FGFR2共扩增1例，HER2/MET/FGFR2共扩增1例，但各基因相互排他性扩增。结论：MLPA和FISH联合研究获得的HER2和其他基因扩增状态的半全面信息可能有助于制定针对胃癌的个体化分子靶向治疗方案。

By combined analysis of immunohistochemistry and fluorescence in situ hybridization (FISH) on 475 formalin-fixed paraffin-embedded tissue, 51 gastric adenocarcinoma with HER2-amplified cancer cells. The heterogeneity of HER2 amplification, if defined as the existence of less than 50% of cancer cells positive for ERBB2 amplification, the 21 tumors (42%) would be heterogeneous. The combined analysis of multiplex ligation-dependent probe amplification (MLPA) and FISH revealed that, co-amplification in individual cells of HER2 and MYC were found in 8 tumors and MYC/FGFR2, and MYC/EGFR in a case respectively. On the other hand, co-amplification of HER2/EGFR in 7, HER2/FGFR2 in one tumor and HER2/MET/FGFR2 in a tumor, however the respective genes were mutually exclusively amplified. In conclusion, the semi-comprehensive information of amplification status of HER2 and other genes obtained by the combined study of MLPA and FISH may be useful to plan individualized molecular target therapy against gastric cancers.