Table 2.

EGFR gene mutations identified

Exon	Amino acid change	Frequency no. (%)a
		EGFR-TKI	Chemo
18	G719Ab	2 (2)	2 (4)
	G719Cc	2 (2)	1 (2)
	G719S	1 (1)	0 (0)
	E709Kd	1 (1)	0 (0)
19	dele	48 (48)	25 (46)
	delinsf	8 (8)	8 (15)
	K754Ee	1 (1)	0 (0)
	I740Tf	1 (1)	0 (0)
	A755Df	1 (1)	0 (0)
	D761Yc	1 (1)	0 (0)
20	T790Mg	4 (4)	4 (7)
	S768Ic	1 (1)	1 (2)
	G779Cb	1 (1)	0 (0)
21	L858Rd	34 (34)	18 (33)
	L861Qb,e,h	8 (8)	0 (0)
	R776Se	1 (1)	0 (0)
	V834Ld	1 (1)	0 (0)
	G873Ee	1 (1)	0 (0)
22	M881Th	1 (1)	0 (0)

Abbreviations: del, deletion; delins, deletion-insertion.

^aTwenty-one patients had more than one EGFR mutation, including one patient with 3 mutations.

^bOne patient had both G719A and G779C; one patient had both G719A and L861Q.

^cOne patient had both G719C and D761Y; two patients had both G719C and S768I.

^dOne patient had both L858R and E709K; one patient had both L858R and V834L.

^eOne patient had both exon 19 del and K754E; one patient had both exon 19 del and R776S; one patient had all of G873E, L861Q, and exon 19 del.

^fOne patient had both exon 19 delins and I740T; one patient had both an exon 19 delins and A755D.

^gAll 8 patients with T790M had concurrent sensitizing EGFR mutations (3 patients with exon 19 del; 2 patients with exon 19 delins; 3 patients with L858R).

^hOne patient had both L861Q and M881T.