Table 1.

Patient characteristics

Characteristics	No. of patients (N = 141)	EGFR-activating mutation < 40 copies/ml (N = 71)	EGFR-activating mutation ≥ 40 copies/ml (N = 70)	P value
Age
Median (range), years	67 (38–88)	69 (38–84)	67 (43–88)	0.42
< 65years	53 (38%)	25 (35%)	28 (40%)	0.56
≥ 65 years	88 (62%)	46 (65%)	42 (60%)
Gender
Female	106 (75%)	54 (76%)	52 (74%)	0.81
Male	35 (25%)	17 (24%)	18 (26%)
Metastases
Lung	43 (31%)	26 (37%)	17 (24%)	0.11
Bone	11 (8%)	2 (3%)	9 (13%)
Brain	8 (6%)	4 (6%)	4 (6%)
Other	79 (56%)	39 (55%)	40 (57%)
EGFR tissue genotype
Exon 19 deletion	90 (64%)	46 (65%)	44 (63%)	0.36
L858R	40 (28%)	20 (28%)	20 (29%)
L861Q	6 (4%)	1 (1%)	5 (7%)
L858R/exon 18 mutation	1 (1%)	0 (0%)	1 (1%)
Exon 18	1 (1%)	1 (1%)	0
G719X, S768I	1 (1%)	1 (1%)	0
L858R, S768I	1 (1%)	1 (1%)	0
L858R, L861Q	1 (1%)	1 (1%)	0
First-line EGFR TKI therapy
Afatinib	60 (43%)	34 (48%)	26 (37%)	0.41
Erlotinib	12 (9%)	7 (10%)	5 (7%)
Gefitinib	41 (29%)	19 (27%)	22 (31%)
> 1 EGFR TKI	28 (20%)	11 (16%)	17 (24%)

Percentages may not total 100, because of rounding

EGFR epidermal growth factor receptor, TKI tyrosine kinase inhibitor