Table 1.

Baseline characteristics of the study population (N = 80)

Characteristics	Total cohort (N = 80)	Gefitinib (N = 16)	Afatinib (N = 30)	Erlotinib (N = 34)	P values
Age, y	64.5 (57.2–70.5)	67.0 (62.5–79.0)	60.5 (54.3–66.0)	65.0 (56.8–69.5)	0.019
Male sex	34 (43)	8 (50)	11 (37)	15 (44)	0.663
ECOG
0–1	74 (93)	14 (88)	27 (90)	33 (97)	0.393
≥2	6 (8)	2 (13)	3 (10)	1 (3)
Smoking status
Current or former smoker	23 (29)	6 (38)	8 (27)	9 (27)	0.688
Never-smoker	57 (71)	10 (63)	22 (73)	25 (74)
Stage
IIIB/IV	73 (91)	14 (88)	27 (90)	32 (94)	0.708
Post-operative recurrence	7 (9)	2 (13)	3 (10)	2 (6)
EGFR mutation
L858R	35 (44)	9 (56)	11 (37)	15 (44)	0.095
Exon 19 deletion	41 (51)	7 (44)	15 (50)	19 (56)
Others†	4 (5)	0 (0)	4 (13)	0 (0)
Initial presentation
Malignant pleural effusion	25 (31)	5 (31)	8 (27)	12 (35)	0.759
Malignant pericardial effusion	3 (4)	0 (0)	1 (3)	2 (6)	0.587
Brain metastasis	29 (36)	2 (13)	8 (27)	19 (56)	0.005
Liver metastasis	7 (9)	2 (13)	1 (3)	4 (12)	0.412
Bone metastasis	40 (50)	7 (44)	13 (43)	20 (59)	0.398
Best response to EGFR TKI
Partial response	55 (69)	9 (56)	24 (80)	22 (65)	0.522
Stable disease	21 (26)	6 (38)	5 (17)	10 (29)
Progressive disease	4 (5)	1 (6)	1 (3)	2 (6)
Time to progression, mo‡	13.8 (8.2–21.6)	14.3 (9.8–25.2)	15.8 (7.2–24.2)	13.3 (7.3–19.0)	0.429
Duration of first-line TKI, mo§	18.5 (11.1–26.1)	22.7 (12.5–31.2)	21.0 (12.0–28.7)	15.1 (9.0–23.6)	0.144
Overall survival, mo¶	36.2 (23.3–54.9)	49.5 (35.5–56.1)	37.5 (23.6–58.1)	33.0 (20.5–40.9)	0.043

ECOG, Eastern Cooperative Oncology Group; EGFR, epidermal growth factor receptor; TKI, tyrosine kinase inhibitor

† G719X, L861Q, and L858R + S768I.

‡ No disease progression was observed in 5 patients at the time of data cutoff (December 2021)

§ In December 2021, 5 patients were still receiving TKI therapy

¶ A total of 28 patients remained alive at the end of 2021