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

作者：Maria E. Arcila, Geoffrey R. Oxnard, Khédoudja Nafa, Gregory J. Riely, Stephen Barnett Solomon, Maureen Frances Zakowski, Mark G. Kris, William J. Pao, Vincent A. Miller, Marc Ladanyi · 发表于：Clinical Cancer Research · 年份：2011 · DOI：10.1158/1078-0432.ccr-10-2277 · 被引用次数：580 · 研究领域：Lung Cancer Treatments and Mutations、Lung Cancer Diagnosis and Treatment、Lung Cancer Research Studies

BACKGROUND: The epidermal growth factor receptor (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 was also analyzed. METHODS: 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. RESULTS: 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). CONCLUSIONS: The re-biopsy of lung ca...