Table 2.

Univariate Cox Regression Analyses of PFS and OS

Variable	PFS			OS
	HR	95% CI	P value	HR	95% CI	P value
Age ≥ 65 (vs Age < 65 years old)	1.182	0.696–2.007	0.536	1.881	1.041–3.397	0.036*
Male (vs female)	1.264	0.708–2.256	0.428	1.312	0.694–2.482	0.403
Squamous (vs other)	1.149	0.607–2.174	0.669	1.504	0.761–2.974	0.240
Adenocarcinoma (vs other)	1.009	0.577–1.765	0.974	0.816	0.449–1.484	0.506
ECOG PS at treatment start	1.085	0.614–1.917	0.779	1.573	0.895–2.766	0.115
Tobacco use (vs none)	1.206	0.703–2.068	0.497	1.854	1.012–3.398	0.046*
Liver metastasis (vs none)	0.909	0.125–6.608	0.925	2.440	0.586–10.154	0.220
Skeletal metastasis (vs none)	1.051	0.593–1.861	0.865	0.799	0.421–1.514	0.491
Brain metastasis (vs none)	0.539	0.213–1.364	0.192	0.607	0.236–1.562	0.300
Lymphatic metastasis (vs none)	0.674	0.339–1.339	0.260	1.314	0.557–3.095	0.533
IV Stage (vs IIIA–IIIB Stage)	0.824	0.443–1.531	0.540	0.638	0.331–1.229	0.179
EGFR mutation (vs non–EGFR mutation)	1.395	0.629–3.096	0.413	0.902	0.356–2.286	0.829
No. of previous treatment lines > 3 (vs ≤ 3)	1.735	1.013–2.974	0.045*	1.112	0.634–1.950	0.710
Previous chemotherapy (vs with no previous therapy)	1.301	0.654–2.587	0.453	0.788	0.386–1.610	0.513
Previous targeted therapy (vs with no previous therapy)	1.463	0.791–2.706	0.226	1.835	0.928–3.626	0.081
Previous targeted therapy (vs with no previous therapy)	1.376	0.798–2.371	0.251	1.120	0.619–2.027	0.708
Previous PD–1 inhibitor (vs with no previous therapy)	1.581	0.216–11.583	0.652	2.658	0.357–19.77	0.340
CRPa	1.002	0.997–1.006	0.479	1.003	0.998–1.007	0.250
ANC	1.105	1.044–1.170	0.001*	1.070	1.023–1.121	0.004*
ALC	0.841	0.567–1.249	0.391	0.862	0.553–1.346	0.515

Note: ^aData were missing in three patients. *p < 0.05.

Abbreviations: EGFR, epidermal growth factor receptor; PD-L1, programmed cell death protein ligand-1; CRP, C–reactive protein; ANC, absolute neutrophil count; ALC, absolute lymphocyte count; HR, hazard ratio; CI, confidence interval.