Table 3. Univariate and multivariate Cox regression analyses of overall survival (N=46).

Variables	HR (95% CI)	P-value	Adjusted HR (95% CI)	P-value
Age
Continuous	0.99 (0.95–1.04)	0.690
Gender
Female	0.84 (0.41–1.74)	0.842
Male	1.00
Histology
Adenocarcinoma	0.36 (0.12–1.10)	0.073
Squamous cell	1.00
Smoking
Never or former	1.37 (0.68–3.01)	0.400
Current	1.00
Performance status, ECOG
0–1	0.60 (0.20–1.74)	0.344
2	1.00
Stage
IV	0.51 (0.15–1.76)	0.287
III	1.00
Erlotinib treatment
Second line	0.69 (0.27–1.75)	0.432
Third line	1.00
Presence of mutated cfDNA
Mutated cfDNA positive	2.26 (1.13–4.55)	0.022	2.11 (1.02–4.38)	0.044
Mutated cfDNA negative	1.00		1.00
TLGa
>420	2.80 (1.41–5.55)	0.003	3.08 (1.46–6.47)	0.003
⩽420	1.00		1.00

Abbreviations: cfDNA=cell-free DNA; CI=confidence interval; ECOG=Eastern Cooperative Oncology Group; HR=hazard ratio; TLG=tumour lesion glycolysis.

^aDivided by the median value.