Table 3.
Cox proportional-hazards regression model for factors affecting overall survival
| Univariate analysis |
Multivariate analysis |
|||||
|---|---|---|---|---|---|---|
| Variable | Median OS (95% CI), months | HR (95% CI) |
P | HR (95% CI) | P | |
| Histology | Squamous | 10.2 (8.6–12.1) | ref | ref | ||
| Non-squamous | 12.1 (10.2–13.5) | 0.86 (0.75–0.99) | .0367 | 0.88 (0.76–1.02) | .0825 | |
| Any grade TRAEs | No | 8.5 (7.4–9.5) | ref | ref | ||
| Yes | 18.3 (15.8–19.4) | 0.55 (0.48–0.64) | .0001 | 0.55 (0.48–0.64) | .0001 | |
| Grade 3–4 TRAEs | No | 10.8 (9.7–12.3) | ref | |||
| Yes | 12.6 (10.9–19.1) | 0.83 (0.65–1.07) | .145 | |||
| ECOG PS | 0-1 | 13.0 (11.9–14.5) | ref | ref | ||
| 2 | 4.9 (4.0–6.3) | 1.97 (1.65–2.36) | .0001 | 1.98 (1.65–2.38) | .0001 | |
| 3-4 | 3.5 (2.1–7.7) | 2.22 (1.61–3.06) | .0001 | 2.22 (1.61–3.06) | .0001 | |
| Brain metastasis | No | 11.9 (10.2–12.8) | ref | |||
| Yes | 9.8 (7.6–12.2) | 1.07 (0.90–1.27) | .4258 | |||
| Symptomatic brain metastasis | No | 11.5 (10.2–12.6) | ref | ref | ||
| Yes | 9.2 (4.9–10.8) | 1.37 (1.03–1.81) | .0283 | 1.38 (1.04–1.84) | .0277 | |
| Active auto-immune disease | No | 11.1 (10.0–12.4) | ref | |||
| Yes | 11.3 (8.3–16.3) | 1.07 (0.74–1.56) | .7071 | |||
| Age | ≥80 | 9.8 (6.7–13.0) | ref | |||
| <80 | 11.3 (10.2–12.5) | 0.92 (0.72–1.17) | .4755 | |||
| PD-L1 | Not expressed | 9.1 (7.6–15.8) | ref | |||
| Expressed | 11.8 (8.9–14.8) | 0.94 (0.66–1.34) | .7364 | |||
| PD-L1 | <50%* | 11.6 (6.7–14.8) | ref | |||
| ≥50%* | 11.8 (7.3–18.4) | 0.93 (0.61–1.43) | .7478 | |||
| Corticosteroids at inclusion | No | 12.0 (10.5–13.0) | ref | ref | ||
| Yes | 5.8 (4.2–8.4) | 1.62 (1.28–2.05) | .0001 | 1.54 (1.22–1.96) | .0004 | |
| EGFR status | Wildtype | 12.2 (10.2–13.8) | ref | ref | ||
| Mutated | 8.1 (4.5–11.3) | 1.50 (1.03–2.18) | .035 | 1.50 (1.02–2.21) | .041 | |
| Smoking status | Current/former smoker | 11.7 (10.2–12.9) | ref | ref | ||
| Never smoked | 8.9 (6.1–11.5) | 1.26 (1.02–1.56) | .0328 | 1.35 (1.07–1.69) | .0109 | |
p-values in bold are significant.
CI, confidence interval; ECOG PS, Eastern Cooperative Oncology Group Performance Status; EGFR, epidermal growth factor receptor; HR, hazard ratio; OS, overall survival; PD-L1, programmed death-ligand 1; ref, reference group; TRAEs, treatment-related adverse events
*% of tumor cells expressing PD-L1
All models were adjusted for age, sex, histology and ECOG PS, except when one of these variables was the main factor of interest, in which case it was not included as an adjustment factor.