Univariate analysis for PFS and OS using Cox proportional hazards regression model in chemotherapy cohort
| Characteristics | PFS | OS | ||
|---|---|---|---|---|
| HR (95% CI) | P | HR (95% CI) | P | |
| Age | 1.03 (0.93–1.15) | 0.594 | 0.99 (0.97–1.02) | 0.522 |
| Gender (male vs. female) | 0.31 (0.02–2.31) | 0.316 | 0.75 (0.40–1.51) | 0.391 |
| BMI | 0.93 (0.70–1.21) | 0.596 | 0.97 (0.90–1.04) | 0.404 |
| ECOG PS (2 vs. 0/1) | 1.67 (0.87–3.02) | 0.102 | 2.33 (1.18–4.38) | 0.011 |
| Smoking (never vs. ever) | 1.42 (0.83–2.45) | 0.198 | 1.26 (0.70–2.26) | 0.432 |
| Histology (squamous vs. non-squamous) | 1.11 (0.64–1.96) | 0.721 | 1.23 (0.67–2.20) | 0.489 |
| PD-L1 expression (< 50% vs. ≥ 50%) | 1.33 (0.66–2.46) | 0.393 | 1.50 (0.71–2.93) | 0.259 |
| Brain metastasis at subsequent line chemotherapy (yes vs. no) | 1.59 (0.48–3.96) | 0.379 | 2.29 (0.66–5.76) | 0.134 |
| Bone metastasis at subsequent line chemotherapy (yes vs. no) | 1.09 (0.45–2.27) | 0.837 | 1.08 (0.47–3.13) | 0.876 |
| Metastatic sites at subsequent line chemotherapy (< 2 vs. ≥ 2) | 1.00 (0.58–1.71) | 0.989 | 0.87 (0.48–1.57) | 0.643 |
| Line of initial ICI therapy (1 vs. 2) | 0.78 (0.30–1.70) | 0.568 | 0.65 (0.20–1.62) | 0.416 |
| Initial ICI regimen (monotherapy vs. combination chemotherapy) | 1.22 (0.67–2.38) | 0.542 | 1.34 (0.68–2.97) | 0.429 |
| Best overall response to initial ICI therapy (CR/PR vs. SD/PD) | 0.92 (0.49–1.69) | 0.790 | 0.83 (0.43–1.54) | 0.574 |
| Duration of initial ICI therapy (≥ 1 year vs. < 1 year) | 0.90 (0.51–1.56) | 0.721 | 0.62 (0.33–1.11) | 0.115 |
| irAEs at initial ICI therapy (yes vs. no) | 0.68 (0.39–1.18) | 0.169 | 0.90 (0.51–1.62) | 0.729 |
| Subsequent line treatment regimen (monotherapy vs. combination chemotherapy) | 1.61 (0.88–3.14) | 0.140 | 1.43 (0.77–2.82) | 0.277 |
| Baseline NLR at subsequent line therapy (≥ 3.8 vs. < 3.8) | 1.22 (0.71–2.09) | 0.468 | 1.58 (0.89–2.83) | 0.121 |
PFS: progression-free survival; OS: overall survival; BMI: body mass index; ECOG PS: Eastern Cooperative Oncology Group Performance Status; NLR: neutrophil-to-lymphocyte ratio; irAEs: immune-related adverse events; HR: hazard ratio; PD-L1: programmed cell death-ligand 1; SD: stable disease; PD: progressive disease; CR: complete response; PR: partial response; ICI: immune checkpoint inhibitor