Table 4. Univariate and multivariate Cox analysis of overall survival.
| Variables | Univariate analysis | Multivariate analysis | |||||
|---|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | ||
| Age (<65 years vs. ≥65 years) | 0.50 | 0.16–1.55 | 0.22 | ||||
| ECOG score (≤1 vs. >1) | 1.61 | 0.51–5.02 | 0.41 | ||||
| Primary tumor | 0.99 | 0.66–1.46 | 0.94 | ||||
| Pathological type (squamous vs. nonsquamous) | 0.72 | 0.27–1.92 | 0.50 | ||||
| Smoking history (yes vs. no) | 0.96 | 0.35–2.62 | 0.94 | ||||
| BED | 1.00 | 0.97–1.04 | 0.91 | ||||
| Number of targets (1 vs. >1) | 1.43 | 0.32–6.35 | 0.63 | ||||
| Chemotherapy (yes vs. no) | 0.76 | 0.17–3.41 | 0.72 | ||||
| Targeted therapy (yes vs. no) | 3.07 | 0.87–10.81 | 0.08 | ||||
| SBRT target size (<2 vs. ≥2 cm) | 1.28 | 0.41–3.97 | 0.67 | ||||
| PTV | 1.03 | 1.00–1.06 | 0.07 | ||||
| Time interval between radiotherapy and immunotherapy ≤21 vs. >21 days | 0.18 | 0.05–0.63 | 0.007 | 0.24 | 0.06–0.89 | 0.03 | |
| ALC before SBRT | 0.38 | 0.11–1.28 | 0.11 | ||||
| NLR before SBRT | 1.23 | 0.89–1.71 | 0.20 | ||||
| ALC after SBRT | 0.07 | 0.01–0.37 | 0.002 | ||||
| NLR after SBRT | 1.14 | 1.06–1.23 | <0.001 | 1.10 | 1.01–1.9 | 0.02 | |
HR, hazard ratio; CI, confidence interval; ECOG, Eastern Cooperative Oncology Group; BED, biologically effective dose; SBRT, stereotactic body radiotherapy; PTV, planning target volume; ALC, absolute lymphocyte count; NLR, neutrophil-to-lymphocyte ratio.