Abstract 1782: Detection of T790M gefitinib resistance mutation in EGFR using the BEAMing method

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), such as gefitinib or erlotinib, are effective therapies for non-small cell lung cancer (NSCLC) patients with primary EGFR mutations. However, most patients who initially respond to treatment with these drugs will develop resistance to EGFR TKIs. The secondary EGFR T790M mutation is reported to correlate with acquired resistance. We examined the T790M mutation in primary tumors with BEAMing (beads, emulsion, amplification, magnetic), which is the most sensitive technique to detect minor mutated alleles. Currently, we can detect point mutation at the level of 1/10,000 using an improved version of the BEAMing. We detected T790M mutant alleles in NSCLCs in 19 out of 270 NSCLCs with primary EGFR mutations. The detection of small fraction of T790M mutant alleles may be useful for predicting resistance of NSCLCs to TKIs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1782.