Presence of the minor EGFR T790M mutation is associated with drug-sensitive EGFR mutations in lung adenocarcinoma patients

Shinsuke Hashida, Junichi Soh, Shinichi Toyooka, Tomoaki Tanaka, Masashi Furukawa, Kazuhiko Shien, Hiromasa Yamamoto, Hiroaki Asano, Kazunori Tsukuda, Koichi Hagiwara, Shinichiro Miyoshi

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The T790M mutation in the epidermal growth factor receptor (EGFR) gene is known to be associated with the acquired resistance of lung adenocarcinoma patients to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). The minor T790M mutant allele is occasionally detected in EGFR-TKI-naive tumor samples, yet findings concerning the clinical impact of the minor T790M mutation vary among previous studies. In the present study, we assessed the clinical impact of the minor T790M mutation using a novel, highly sensitive assay combining high-resolution melting (HRM), mutant-enriched PCR and co-amplification at a lower denaturation temperature (COLD)-PCR. We determined the T790M mutational status in 146 surgically resected lung adenocarcinomas without a history of EGFR-TKI treatment using mutant-enriched COLD-HRM (MEC-HRM) and standard HRM assays. The sensitivities of the MEC-HRM and standard HRM assays for the detection of T790M-mutant alleles among wild-type alleles were 0.01 and 10%, respectively. Although the T790M mutation was not detected using a standard HRM assay, we identified 19 (13%) T790M mutations using the MEC-HRM assay and defined these 19 mutations as minor T790M mutations. The proportion of T790M alleles was <0.1% in 17 (84%) of the 19 samples. Multivariate analyses revealed that a minor T790M mutation was significantly associated with the presence of EGFR exon 19 deletions or the L858R mutation (both of which are drug-sensitive EGFR mutations) (P=0.04). In conclusion, the minor EGFR T790M mutations were present in 13% of EGFR-TKI-naive surgically resected lung adenocarcinomas and were associated with drug-sensitive EGFR mutations.

Original languageEnglish
Pages (from-to)145-152
Number of pages8
JournalOncology reports
Volume32
Issue number1
DOIs
Publication statusPublished - Jul 2014

Keywords

  • COLD-PCR
  • Drug resistance
  • High resolution melting analysis
  • Mutant-enriched PCR
  • T790M mutation

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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