Establish of new deteciton of EGFR mutation status using immunostaining in non-small cell lung cancer

为了建立检测非小细胞肺癌患者EGFR突变状态的方法，我们采用了PNA-LNA聚合酶链式反应钳夹法和免疫组织化学方法。133例标本中，EGFR突变特异性抗体阳性37例(27.8%)，阴性85例(63.9%)，可疑11例(8.3%)。免疫染色显示37例患者EGFR表达阳性，其中35例(94.6%)DNA检测也呈阳性。在85例EGFR免疫染色阴性的患者中，77例(90.6%)在DNA检测中也是阴性的。在接受EGFR-TKIs治疗的非小细胞肺癌患者中，EGFR阳性表达的患者在开始治疗后的无进展生存期显著长于那些表达可疑和阴性的患者(P=0.002)。我们的结果表明，EGFR突变特异性抗体的免疫染色是一种新的检测EGFR-TKI抑制的方法，并可作为患者管理的有用指标。

To establish a testing algorithm for EGFR mutation status in NSCLC patients, we utilized PNA-LNA PCR clamp assay and immunostaining. In the 133 samples, positive, negative and equivocal results for EGFR mutation-specific antibodies were observed in 37 patients (27.8%), 85 patients (63.9%) and 11 patients (8.3%), respectively. Thirty-seven patients showed positive EGFR expression by immunostaining, and 35 (94.6%) of these also tested positive in the DNA-based assay. Of 85 EGFR-negative patients by immunostaining, 77 (90.6%) also tested negative in the DNA-based assay. In NSCLC patients treated with EGFR-TKIs, the progression-free survival after the start of EGFR-TKIs treatment was significantly longer in patients with EGFR positive expression than in those with equivocal and negative expression (P = 0.002). Our results suggest immunostaining for EGFR mutation-specific antibodies are a new test for EGFR-TKI inhibition and could be a useful indicator with regard to patient management.