Table 2. Qualitative analyses of trials according to EGFR mutation status and laboratory methods used to confirm EGFR mutation status

	Study [ref.]
	NEJ002 [12, 23]	WJTOG3405 [13, 25]	IPASS^# [8, 14]	EURTAC [9]	LUX-Lung 3 [15]	OPTIMAL [10]	LUX-Lung 6 [16]	ENSURE [17]
Included patient group	EGFR mutant and absence of T790M	Del19 and L8585R	Nonsmoker or former light smoker (no EGFR status required)	Del19 or L858R	EGFR mutation-positive	Del19 or L858R	EGFR mutation-positive	Del19 or L858R
EGFR mutations that could be included	Del19 L858R Other (not described)	Del19 L858R	Del19 (19 different deletions) L858R T790M L861Q G719X S768I Three insertions in exon 20	Del19 L858R	Del19 (19 different deletions) L858R T790M L861Q G719X S768I Three insertions in exon 20	Del19 L858R	Del19 (19 different deletions) L858R T790M L861Q G719X S768I Three insertions in exon 20	Del19 or L858R
Testing methodology used	Peptide nucleic acid-locked nucleic acid PCR clamp method	For those tested centrally, detection by fragment analysis for Del19 and by cycleave for L858R; confirmed by direct sequencing	Detection by Therascreen EGFR29 in central laboratory	Sanger sequencing confirmed by PNAClamp for Del19 and by TaqMan assay for L858R	Standardised allele-specific quantitative real-time PCR kit (Therascreen EGFR 29) in central laboratory	PCR-based direct sequencing in central laboratory	TheraScreen EGFR RGQ PCR kit in central laboratory	Not reported
Specificity	100% [28]	Direct sequencing: 100% [29]	100% [29]	100% [28]	100% [29]	100% [29]	100% [29]
Sensitivity	89% [28]	Direct sequencing: 40–89% [29]	40–67% [29]	89% for PNAClamp [28] 99% for TaqMan	40–67% [29]	40–89% [29]	40–67% [29]

EGFR: epidermal growth factor receptor; WJTOG: West Japan Thoracic Oncology Group; NEJ002: North East Japan 002; IPASS: Iressa Pan-Asia Study; EURTAC: European Randomised Trial of Tarceva versus Chemotherapy ^#: all patients. Therascreen EGFR 29 and TheraScreen EGFR RGQ PCR kit are manufactured by Qiagen (Manchester, UK); TaqMan is manufactured by Life Technologies Europe BV (Bleiswijk, the Netherlands); PNAClamp is manufactured by Panagene Inc. (Daejeon, Korea).