Table 2– Comparison of EGFR mutational status of biopsy and resected non-small cell lung cancer specimens

First author, year [ref.]	Population studied	Cases with paired biopsy and resection n	Detection methods	Tumour enrichment strategy	EGFR mutation in both biopsy and resection	EGFR WT in both biopsy and resection	EGFR mutation in biopsy and EGFR WT in resection	EGFR WT in biopsy and EGFR mutation in resection	*Discordance rate between biopsy versus* resection**
Solomon, 2010 [26]	Stage I/II ADC (neoadjuvant gefitinib)	16	DS	NA	31.3	68.7	0	0	0
Masago, 2008 [27]	Paired biopsy and resection specimens	19	DS	MD	47.4	47.4	0	5.3^#	0^#
Han, 2012 [28]	Paired biopsy and resection with	23	DS	NA	52.2	47.8	0	0	0
	>20% tumour cellularity		PNA clamping		52.2	30.4	17.4	0	17.4

Data are presented as %, unless otherwise stated. EGFR: epidermal growth factor receptor; WT: wild-type; ADC: adenocarcinoma; DS: direct Sanger sequencing; NA: not available; MD: microdissection; PNA: peptide–nucleic acid. ^#: the amount of DNA from one biopsy specimen was not sufficient and only one exon (exon 19) was sequenced and demonstrated to be wild type, and the corresponding resection specimen showed L858R mutation in exon 21; therefore, this case was not counted as discordant.