Table 2.

Multivariable Cox proportional hazard model analysis according to tumor location.

Variable	Model 1			Model 2
	HR	95% CI	P value	HR	95% CI	P value
Tumor location, lower lobe	1.34	1.14–1.59	0.001	1.31	1.01–1.70	0.039
Age ≥ 60 year	1.72	1.40–2.12	< 0.001	1.63	1.19–2.24	0.003
Sex, male	0.82	0.62–1.10	0.18	1.33	0.84–2.11	0.23
Ever smoking	1.45	1.09–1.93	0.011	1.58	0.98–2.55	0.06
ECOG ≥ 2	2.25	1.76–2.87	< 0.001	2.00	1.39–2.89	< 0.001
Presence of symptoms	1.41	1.17–1.70	< 0.001	1.24	0.94–1.63	0.13
BMI: 23.0–24.9 kg/m2	0.86	0.70–1.05	0.14	0.84	0.62–1.15	0.29
BMI: ≥ 25.0 kg/m2	0.88	0.72–1.07	0.19	0.79	0.58–1.08	0.14
SUV of main mass ≥ 11.2	1.41	1.19–1.69	< 0.001	1.31	1.00–1.71	0.050
Stage II	1.47	0.97–2.25	0.07	1.21	0.65–2.26	0.54
Stage III	3.36	2.40–4.71	< 0.001	3.40	2.06–5.61	< 0.001
Stage IV	8.98	6.64–12.15	< 0.001	9.01	5.64–14.38	< 0.001
ALK translocation	0.42	0.27–0.66	< 0.001	0.27	0.13–0.56	< 0.001
Active treatment	0.33	0.23–0.47	< 0.001	0.46	0.28–0.77	0.003
Adenocarcinoma				1.06	0.74–1.52	0.74
NSE ≥ 16.3 ng/mL				1.42	1.09–1.85	0.009
CYFRA ≥ 3.3 ng/mL				1.55	1.17–2.06	0.002
EGFR mutations				0.46	0.33–0.63	< 0.001

Possible mediational factors (adenocarcinoma, NSE, CYFRA 21-1, EGFR) were excluded in analysis with model 1 and included in analysis with model 2.

ALK anaplastic lymphoma kinase; BMI body mass index; CYFRA cytokeratin fragment; NSE neuron-specific enolase; SUV standardized uptake value.