Table 1. Summary of rebiopsy studies and the molecular and histological alterations.

Rebiopsy studies	Mechanisms of resistance to EGFR inhibitors analyzed	Histological alterations in the resistant tumor
Arcilla et al.	Pretreatment EGFR mutation: 100%
	T790M:
	Standard sequencing: 49%
	Fragment Analysis 53%	Not performed
	Combined standard and LNA-PCR/sequencing: 70%
	MET amplification: 11%
Sequist et al.	Pretreatment EGFR mutation: 100%
	T790M: 49%	SCLC transformation: 14%
	MET amplification: 5%
	PIK3CA mutation: 5%	ETM: 8%
	β-catenin mutations: 5% (all with T790M mut)
Oxnard et al.	T790M: 62%	Not performed
Ohashi et al.	B-RAF: 1%	Not performed

SCLC, small cell lung cancer; EMT, Epithelial to mesenchymal transition