First-generation EGFR tyrosine kinase inhibitor therapy in 106 patients with compound EGFR -mutated lung cancer: a single institution’s clinical practice experience

Cancer Communications

Table 1 Clinicopathological characteristics of lung cancer patients with compound EGFR mutations

Variable	Single common mutation (n = 115)	Compound mutations (n = 106)	P ^†	Double common mutations (n = 5)	P ^†	Common + rare mutations (n = 11)	P ^†	Rare + rare mutations (n = 13)	P ^†	Rare + T790M mutations (n = 8)	P ^†	Common + T790M mutations (n = 69)	P ^†
Sex
Female	56	55	0.635	1	0.368	6	0.711	6	0.862	4	0.943	38	0.402
Male	59	51	0.635	4	0.368	5	0.711	7	0.862	4	0.943	31	0.402
Age (years)
< 60	57	63	0.141	2	0.675	5	0.794	8	0.413	7	0.063	41	0.195
≥ 60	58	43	0.141	3	0.675	6	0.794	5	0.413	1	0.063	28	0.195
Smoking status			0.270		0.118		0.795		0.442		0.795		0.022
Non-smoker	69	69		1		5		4		5		54
Smoker	34	24		3		3		4		3		11
Unknown	12	13		1		0		5		0		4
Tumour status			0.034		0.592		0.782		0.753		0.103		0.064
Recurrence	36	20		1		3		3		0		13
Initial IIIb–IV	79	86		4		8		10		8		56
ECOG PS
0–1	107	96	0.501	4	0.327	9	0.212	13	0.326	6	0.071	64	0.941
2–4	8	10	0.501	1	0.327	2	0.212	0	0.326	2	0.071	5	0.941
Pathology			0.529		0.141		0.672		0.899		0.948		0.534
ADC	110	102		4		10		13		8		67
SCC	5	2		0		1		0		0		1
LELC	0	1		1		0		0		0		0
ASC	0	1		0		0		0		0		1
Timing of TKI			0.720		0.914		0.835		0.803		0.805		0.460
First line	52	55		2		5		6		3		39
Second line	55	46		3		6		7		5		25
Third line	7	4		0		0		0		0		4
Fourth line	1	1		0		0		0		0		1
TKI selection			0.034		0.981		0.592		0.214		0.161		0.021
Gefitinib	64	47		3		5		4		2		33
Erlotinib	26	41		1		4		4		4		28
Icotinib	25	18		1		2		5		2		8
Response to TKIs
PD	10	14	0.088	1	0.148	2	0.652	2	0.328	4	0.012	5	0.293
SD	21	33		1		3		5		1		22
PR	77	54		3		5		5		3		39
CR	1	0		0		0		0		0		0
NE	6	5		0		1		1		0		3

ECOG PS Eastern Cooperative Oncology Group performance status, ADC adenocarcinoma, SCC squamous cell carcinoma, LELC lymphoepithelioma-like carcinoma, ASC adenosquamous carcinoma, PD progressive disease, SD stable disease, PR partial response, CR complete response, NE not evaluated, TKI tyrosine kinase inhibitor, PFS progression-free survival, OS overall survival
^†All variables of different subgroups were compared with the single common mutation group; P < 0.05 was defined as significantly different