Table 3.

Multivariate Analysis of PFS

Clinical Variable	PFS
	Univariate Analysis		Multivariate Analysis
	HR (95% CI)	P value	HR (95% CI)	P value
Age	1.022 (1.001–1.043)	0.036
Initial CEA (n=112)	1.000 (1.000–1.000)	0.672
Sex
Male (n=45)	1.000 (ref.)
Female (n=69)	1.117 (0.667–1.872)	0.673
Smoke history
Never smoke (n=77)	1.000 (ref.)
Current and ex-smoker (n=37)	0.974 (0.572–1.660)	0.923
Histology
Adenocarcinoma (n=112)	1.000 (ref.)
Adenosquamous or NOS (n=2)	0.047 (0.000–40.385)	0.375
Performance status
0–1 (n=81)	1.000 (ref.)		1.000 (ref.)
2–4 (n=33)	3.648 (2.172–6.129)	<0.001	3.822 (1.994–7.326)	<0.001
EGFR
Exon 19 (n=55)	1.000 (ref.)
Exon 21 (n=53)	1.219 (0.728–2.040)	0.451
Other exon (18 or 20) (n=6)	1.236 (0.374–4.086)	0.729
Weight loss on initial diagnosis
No (n=76)	1.000 (ref.)
Yes (n=38)	1.328 (0.796–2.217)	0.277
Post operation recurrence
No (n=111)	1.000 (ref.)
Yes (n=3)	0.313 (0.043–2.268)	0.250
Distant metastasis on Initial diagnosis
No (n=30)	1.000 (ref.)		1.000 (ref.)
Yes (n=84)	2.130 (1.141–3.974)	0.018	2.432 (1.248–4.737)	0.009
Pleural metastasis on Initial diagnosis
No (n=75)	1.000 (ref.)
Yes (n=39)	1.425 (0.842–2.412)	0.187
Brain metastasis
No (n=75)	1.000 (ref.)
Yes (n=39)	1.625 (0.955–2.765)	0.073
PD-L1
<1% (n=54)	1.000 (ref.)
1–49% (n=50)	0.816 (0.479–1.390)	0.454
≥50% (n=10)	0.840 (0.350–2.015)	0.696
EGFR-TKI
Gefitinib (n=42)	1.000 (ref.)		1.000 (ref.)
Erlotinib (n=36)	0.781 (0.445–1.371)	0.389
Afatinib (n=36)	0.365 (0.185–0.722)	0.004	0.463 (0.226–0.952)	0.036
EGFR-TKI + anti-angiogenesis
No (n=101)	1.000 (ref.)
Yes (n=13)	0.613 (0.245–1.536)	0.297

Abbreviations: CEA, carcinoembryonic antigen; CI, confidence interval; EGFR, epidermal growth factor receptor; NOS, not otherwise specified; OS, overall survival; PD-L1, programmed cell death-ligand 1; PFS, progression-free survival; ref., reference.