Table 2.
Cox Proportional Hazards Model for OS since the Start of Chemotherapy, Stratified by Histologic Subtype
| PD-L1 Expression | All Patients⁎ | Adenocarcinoma | Squamous Cell Carcinoma |
|---|---|---|---|
| PD-L1 negative | |||
| N/Deaths | 51/48 | 30/29 | 9/7 |
| Median OS (95% CI), months | 7.5 (6.4-12.4) | 10.7 (7.1-16.4) | 19.9 (3.3-NR) |
| PD-L1 weak positive | |||
| N/Deaths | 99/91 | 51/46 | 24/24 |
| Median OS (95% CI), months | 9.8 (8.2-12.3) | 12.1 (8.5-15.0) | 8.8 (6.1-12.2) |
| Crude HR (95% CI) | 1.04 (0.73-1.49) | 0.86 (0.54-1.36) | 2.76 (1.09-7.03) |
| Adjusted HR (95% CI)† | 1.09 (0.76-1.58) | 0.84 (0.53-1.34) | 2.36 (0.84-6.63) |
| PD-L1 strong positive | |||
| N/Deaths | 51/49 | 24/24 | 9/9 |
| Median OS (95% CI), months | 9.0 (6.4-11.1) | 10.9 (6.9-13.3) | 7.2 (0.9-10.2) |
| Crude HR (95% CI) | 1.31 (0.88-1.97) | 1.27 (0.74-2.19) | 4.88 (1.56-15.14) |
| Adjusted HR (95% CI)† | 1.36 (0.90-2.06) | 1.31 (0.76-2.27) | 3.87 (1.05-14.26) |
| PD-L1 strong or weak positive | |||
| N/Death | 150/140 | 75/70 | 33/33 |
| Median OS (95% CI), months | 9.3 (7.8-11.0) | 11.1 (9.2-13.3) | 8.4 (6.6-9.8) |
| Crude HR (95% CI) | 1.12 (0.80-1.57) | 0.96 (0.62-1.48) | 3.01 (1.21-7.51) |
| Adjusted HR (95% CI)† | 1.17 (0.83-1.66) | 0.96 (0.62-1.48) | 2.40 (0.87-6.60) |
NR, not reached.
⁎
The date of the first dose of chemotherapy was missing for 3 patients; therefore, only 201 patients are included in survival analysis.
†
HR: adjusting for age, sex, smoking status, histology, and performance status, with the PD-L1–negative group as the reference.