EGFR在甲状腺乳头状癌中突变及表达的临床病理分析

Clinicopathological Significance of EGFR Gene Mutation and Its Encoding Protein Expression in Papillary Thyroid Carcinoma

目的探讨甲状腺乳头状癌(papillary thyroid carcinoma,PTC)表皮生长因子(epidermal growth factor receptor,EGFR)基因突变及其编码蛋白质表达的临床病理意义。方法应用蝎形探针扩增阻遏突变系统(amplification refractory mutation system,ARMS)和免疫组织化学方法分别检测99例PTC组织中EGFR基因突变和EGFR表达并分析其临床病理意义。结果EGFR蛋白在淋巴结转移PTC组的表达水平高于无淋巴结转移者(P<0.05),而肿瘤是否甲状腺外侵、临床分期等参数均与HER1蛋白表达无相关性(P>0.05)。未见EGFR基因第18、19、20、21共4个外显子的好发热点位点在99例PTC组织中发生突变,类似于癌症基因组图谱(the cancer genome atlas,TCGA)数据库的研究结论。结论PTC组织中存在EGFR蛋白过表达的现象,PTC的淋巴结转移率随之升高,与此同时未能在相应的PTC组织中检测到EGFR基因常见第18、19、20、21共4个外显子的突变,因此运用于非小细胞肺癌的拮抗EGFR酪氨酸激酶的靶向药可能不能成为治疗PTC的选择方案。

Objective To investigate the clinicopathological significance of epidermal growth factor(EGFR)gene mutation and EGFR protein expression in papillary thyroid carcinoma(PTC).Methods Scorpion probe amplification repressor mutation system(ARMS)and immunohistochemistry were used to detect EGFR gene mutation and EGFR protein expression in 99 PTC tissues.The clinicopathological significance was analyzed correspondingly.Results The expression level of EGFR protein in PTC group with lymph node metastasis was higher than that in those without lymph node metastasis(P<0.05).There was no correlation between EGFR protein expression and tumor extrathyroid invasion,clinical stage and other parameters(P>0.05).No common mutation of EGFR gene Exon18,19,20,21 was found in 99 PTC cancer tissues,which was analogue to the research data of EGFR gene in PTC from the cancer genome atlas(TCGA)database.Conclusion The overexpression of EGFR protein in PTC tissue increases the lymph node metastasis rate of PTC.At the same time,the mutation of exon 18,19,20,21 of EGFR gene is not detected in the corresponding PTC tissue.Therefore,the targeted drugs against EGFR tyrosine kinase used in non-small cell lung cancer may not be the choice for the treatment of PTC.