Erlotinib usage after prior treatment with gefitinib in advanced non-small cell lung cancer: A clinical perspective and review of published literature

Table 2 Prevalence of epidermal growth factor receptor mutations and comparison of responses to gefitinib and erlotinib n (%)

Ref.	No. ofpatients	EGFRmutations no	E19 Del/E21L858R	Response to prior gefitinib				Response to erlotinib
				CR	PR	SD	PD	CR	PR	SD	PD
Garfield[9]	1	NA	NA				1(100)		1(100)
Viswanathan et al[16]	5	NA	NA		4(80.0)		1(20.0)				5(100)
Walther et al[17]	1	NA	NA				1(100)		1(100)
Chang et al[18]	1	1 (100)	1/0		1(100)				1(100)
Cho et al[19]	21	5 (23.8)	5/0		6(28.6)	4(19.0)	11(52.4)		2(9.5)	4(19.0)	15(71.5)
Gridelli et al[32]	3	NA	NA			3(100)			1(33.3)	2(66.7)
Kim et al[33]	1	NA	NA		1(100)				1(100)
Costa et al[23]	181	17 (94.4)	4/13		11(84.6)	2(15.4)			1(7.7)	2(15.4)	10(76.9)
Lee et al[21]	23	3 (13.0)	3/0		15(65.2)	2(8.7)	6(26.1)		1(4.3)	1(4.3)	21(91.4)
Vasile et al[22]	8	NA	NA		4(50.0)	4(50.0)			2(25.0)	3(37.5)	3(37.5)
Wong et al[20]	14	7 (50.0)	4/3		9(64.3)		5(35.7)			5(35.7)	9(64.3)
Wong et al[34]	1	1 (100)	1/0		1(100)					1(100)
Wu et al[35]	1	1 (100)	0/1		1(100)					1(100)
Katayama et al[36]	7	6 (85.7)	4/2	2(28.6)	2(28.6)	3(42.8)			3(42.9)	3(42.9)	1(14.3)
Sim et al[24]	16	5 (31.3)	2/3		9(56.3)	2(12.5)	5(31.2)		1(6.3)	3(18.7)	12(75.0)
Zhou et al[25]	21	7 (33.3)	NA/NA	2(9.5)		8(38.1)	11(52.4)		2(9.5)	4(19.1)	15(71.4)
Wong et al[26]	21	3 (14.3)	0/3		18(85.7)		3(14.3)		12(57.1)		9(42.9)
Asami et al[27]	42	28 (66.7)	14/14		22(52.4)	17(40.5)	3(7.1)		1(2.4)	24(57.1)	17(40.5)
Hata et al[29]	1252	63 (50.4)	NA/NA	3(2.5)	68(56.2)	22(18.2)	28(23.1)		11(8.8)	44(35.2)	70(56.0)
Masuda et al[37]	3	3 (100)	2/1		3(100)				3(100)
Shoji et al[38]	1	0 (0)	0 (0)				1(100)		1(100)
Song et al[39]	20	5 (25.0)	3/2		5(25.0)	9(45.0)	6(30.0)			7(35.0)	13(65.0)
Takenaka et al[40]	1	1 (100)	1/0			1(100)			1(100)
Saito et al[41]	21	12 (57.1)	0/12		16(76.2)	5(23.8)			2(9)	6(19)	13(62)
Tetsumoto et al[42]	2	2 (100)	1/1		2(100)				2(100)
Koyama et al[43]	54	44 (81.5)	22/22	4(7.4)	32(59.3)	13(24.0)	5(9.3)	0 (0)	4(7.4)	30(55.6)	20(37.0)

¹Response to gefitinib and erlotinib was evaluable for 13 patients only;

²Response to gefitinib was evaluable for 121 patients only. EGFR: Epidermal growth factor receptor; PR: Partial response; CR: Complete response; PD: Progressive disease; SD: Stable disease; E19: Exon 19; E21: Exon 21; Del: Deletion; NA: Not available.