Rebiopsy of lung cancer patients with acquired resistance to EGFR inhibitors and enhanced detection of the T790M mutation using a locked nucleic acid-based assay.
Rebiopsy of lung cancer patients with acquired resistance to EGFR inhibitors and enhanced detection of the T790M mutation using a locked nucleic acid-based assay.
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DOI：
10.1158/1078-0432.ccr-10-2277
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发表时间：
2011-03-01
期刊：
影响因子：
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通讯作者：
Ladanyi M
中科院分区：
文献类型：
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作者：
Arcila ME;Oxnard GR;Nafa K;Riely GJ;Solomon SB;Zakowski MF;Kris MG;Pao W;Miller VA;Ladanyi M
EGFR突变T790 M在约50%的对EGFR抑制剂具有获得性耐药性的肺癌中报告，并且是潜在的预后和预测生物标志物。其评估可能是具有挑战性的，由于有限的组织可用性和低突变等位基因水平的检测不足。在这里，我们试图确定肿瘤再活检的可行性，并使用高灵敏度的锁核酸（LNA）PCR/测序分析更准确地评估T790 M的患病率。还分析了MET扩增。对获得性耐药患者进行再活检，并对样本进行EGFR突变敏感性研究。使用基于PCR的标准方法评价T790 M阳性病例，并使用LNA-PCR/测序方法重新评价一个子集，分析灵敏度约为0.1%。通过FISH评估MET扩增。在121例接受组织采样的患者中，104例（86%）成功分析了致敏EGFR突变。大多数失败与低肿瘤含量有关。所有患者（61/61）匹配的治疗前和耐药标本显示原始致敏EGFR突变一致。对99例患者进行标准T790 M突变分析，检测到51例（51%）突变体。通过基于LNA的方法对30例阴性患者进行重新检测，检测到11个额外的突变体，估计患病率为68%。MET扩增率为11%（4/37）。获得性耐药肺癌患者的再活检是可行的，并为大多数患者的突变分析提供了足够的材料。使用高灵敏度的方法，T790 M在高达68%的这些患者中被检测到。
The EGFR mutation T790M is reported in approximately 50% of lung cancers with acquired resistance to EGFR inhibitors and is a potential prognostic and predictive biomarker. Its assessment can be challenging due to limited tissue availability and underdetection at low mutant allele levels. Here, we sought to determine the feasibility of tumor rebiopsy and to more accurately assess the prevalence of the T790M using a highly sensitive locked nucleic acid (LNA) PCR/sequencing assay. MET amplification is also analyzed. Patients with acquired resistance were rebiopsied and samples were studied for sensitizing EGFR mutations. Positive cases were evaluated for T790M using standard PCR-based methods and a subset were re-evaluated with an LNA-PCR/sequencing method with an analytical sensitivity of approximately 0.1%. MET amplification was assessed by FISH. Of 121 patients undergoing tissue sampling, 104 (86%) were successfully analyzed for sensitizing EGFR mutations. Most failures were related to low tumor content. All patients (61/61) with matched pretreatment and resistance specimens showed concordance for the original sensitizing EGFR mutation. Standard T790M mutation analysis on 99 patients detected 51(51%) mutants. Retesting of 30 negative patients by the LNA-based method detected 11 additional mutants for an estimated prevalence of 68%. MET was amplified in 11% of cases (4/37). The re-biopsy of lung cancer patients with acquired resistance is feasible and provides sufficient material for mutation analysis in most patients. Using high sensitivity methods, the T790M is detected in up to 68% of these patients.