采用灵敏度不同的两种方法检测含有不同比例肿瘤细胞的肺腺癌样本中EGFR的突变状态
Detection of EGFR Mutation Status in Lung Adenocarcinoma Specimens with Different Proportions of Tumor Cells Using Two Methods of Differential Sensitivity
中文摘要:
引言：本文旨在通过灵敏度不同的两种方法，检测含有不同比例肿瘤细胞的肺腺癌样本中的表皮生长因子受体（EGFR）的突变状态。 方法：通过肽核酸（PNA）钳制法和直接测序法测定EGFR的突变状态。样本包括41个含有不同比例肿瘤细胞的恶性胸腔积液细胞块，以及23例含有20%以上肿瘤细胞的肺活检标本和相应的经手术切除的肿瘤。 结果：在恶性胸腔积液的分析中，9例对EGFR酪氨酸激酶抑制剂显示部分缓解的患者中仅有4例通过PNA钳制法检测出EGFR突变；这4例患者的全部细胞块中含有的肿瘤细胞均少于20%。对EGFR酪氨酸激酶抑制剂有效的5例疾病进展的患者中，有1例通过直接测序法显示为野生型EGFR，但PNA钳制法显示为突变型EGFR；该患者的细胞块中含有高比例的肿瘤细胞。比较含有大量肿瘤细胞的活检样本和相应手术切除的肿瘤显示，4例采用PNA钳制法检测的患者的EGFR突变状态不一致，但直接测序法未见有差异。 结论：高灵敏度方法，如PNA钳制法，对于检测含有肿瘤细胞较低的诊断样本的EGFR突变状态可能优于直接测序法。当诊断样本肿瘤细胞比例较高时，直接测序法可能更具代表性。
英文摘要:
Introduction: To evaluate epidermal growth factor receptor (EGFR) mutation status in lung adenocarcinoma specimens with different proportions of tumor cells using two methods with different sensitivities. Methods: EGFR mutation status was determined by peptide nucleic acid (PNA) clamping and direct sequencing. The samples consisted of 41 cell blocks of malignant pleural effusions with various proportions of tumor cells, as well as 23 lung biopsy specimens containing more than 20% tumor cells and the corresponding surgically resected tumors. Results: In the analysis of malignant pleural effusions, EGFR mutations were detected only by PNA clamping in four of nine patients who exhibited partial response to EGFR tyrosine kinase inhibitors; all the cell blocks of these four patients contained less than 20% tumor cells. Direct sequencing revealed wild-type EGFR, whereas PNA clamping revealed mutant EGFR, in one of five patients who exhibited progressive disease in response to EGFR tyrosine kinase inhibitor; the cell block of this patient contained a high proportion of tumor cells. A comparison of biopsy specimens containing sufficient tumor cells and the corresponding surgically resected tumors revealed discordance in the EGFR mutation status in four patients based on PNA clamping, whereas no discrepancies were observed by direct sequencing. Conclusions: Highly sensitive methods, such as PNA clamping, may be superior to direct sequencing for the detection of EGFR mutations in diagnostic specimens with a low proportion of tumor cells. Direct sequencing may be more representative when diagnostic specimens with a high proportion of tumor cells are available. |
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