Table 1.

Patients’ characteristics by metastatic site

	All patients	Bone metastasis	Liver metastasis	Pleural effusion
	n = 50	n = 17	n = 4	n = 13
Patients’ characteristics	n (%)	n (%)	n (%)	n (%)
Age (years)	74.0 (38.0–88.0)	72.0 (38.0–83.0)	71.0 (66.0–80.0)	80.00 (38.0–88.0)
Sex
Male	21 (42.0)	7 (41.2)	2 (50.0)	5 (38.5)
Female	29 (58.0)	10 (58.8)	2 (50.0)	8 (61.5)
Smoking status
Smoker	14 (28.0)	6 (35.3)	3 (75.0)	2 (15.4)
Non‐smoker	36 (72.0)	11 (64.7)	1 (25.0)	11 (84.6)
Performance status
0	19 (38.0)	5 (29.4)	0 (0.0)	1 (7.7)
1	27 (54.0)	11 (64.7)	3 (75.0)	9 (69.2)
2	4 (8.0)	1 (5.9)	1 (25.0)	3 (23.1)
Histological subtype
Adenocarcinoma	49 (98.0)	17 (100.0)	4 (100.0)	12 (92.3)
Squamous cell carcinoma	1 (2.0)	0 (0.0)	0 (0.0)	1 (7.7)
Stage
IIIB	1 (2.0)	0 (0.0)	0 (0.0)	0 (0.0)
IV	34 (68.0)	15 (88.2)	4 (100.0)	12 (92.3)
Postoperative recurrence	15 (30.0)	2 (11.8)	0 (0.0)	1 (7.7)
EGFR mutation status
Exon 19 deletion	25 (50.0)	7 (41.2)	3 (75.0)	6 (46.2)
Exon 21 L858R	25 (50.0)	10 (58.8)	1 (25.0)	7 (53.8)
EGFR‐TKI
Gefitinib	47 (94.0)	15 (88.2)	4 (100.0)	13 (100.0)
Erlotinib	3 (6.0)	2 (11.8)	0 (0.0)	0 (0.0)
No. metastatic organs
1	45 (90.0)	15 (88.2)	2 (50.0)	13 (100.0)
≥2	5 (10.0)	2 (11.8)	2 (50.0)	0 (0.0)