Highly sensitive and noninvasive detection of epidermal growth factor receptor T790M mutation in non-small cell lung cancer.

•We developed and validated a mutant-enriched PCR for the EGFR T790M mutation.•The mutant-enriched PCR could detect the EGFR T790M mutation in plasma samples.•The mutant-enriched PCR detected more EGFR T790M mutation than direct sequencing.•The EGFR T790M mutation was frequent in patients with EGFR activating mutations.•Patients with EGFR T790M mutation have a better prior efficacy of gefitinib.