Table 4.
The relationship between clinicopathological factors and the expression level of (a) PD-L1 in NPCs, (b) PD-1 in NPCs
| Clinicopathological factors | RR | 95% CI | p value | Heterogeneity | No. of studies | Statistical model used | |
|---|---|---|---|---|---|---|---|
| I2 (%) | p value | ||||||
| (a) | |||||||
| Gender: male | 1.02 | (0.96, 1.09) | 0.45 | 0 | 0.70 | 13 | Fixed |
| T stage ≥ 3 | 1.00 | (0.89, 1.13) | 0.88 | 42 | 0.07 | 11 | Random |
| N stage ≥ 2 | 0.98 | (0.87, 1.10) | 0.77 | 34 | 0.12 | 11 | Fixed |
| Metastasis | 0.83 | (0.52, 1.33) | 0.45 | 0 | 0.45 | 4 | Fixed |
| Stage III or IV | 1.07 | (0.99, 1.15) | 0.08 | 38 | 0.12 | 9 | Fixed |
| Undifferentiated | 0.99 | (0.84, 1.18) | 0.94 | 54 | 0.07 | 5 | Random |
| Tobacco use: smoker | 0.91 | (0.78, 1.07) | 0.24 | 0 | 0.43 | 8 | Fixed |
| Alcohol use: drinker | 0.73 | (0.49, 1.09) | 0.13 | 0 | 0.63 | 2 | Fixed |
| EBV positive | 1.03 | (0.93, 1.15) | 0.54 | 29 | 0.24 | 2 | Fixed |
| (b) | |||||||
| Gender: male | 1.04 | (0.96, 1.13) | 0.35 | 0 | 0.99 | 6 | Fixed |
| T stage ≥ 3 | 0.93 | (0.81, 1.07) | 0.29 | 0 | 0.66 | 4 | Fixed |
| N stage ≥ 2 | 1.11 | (0.95, 1.29) | 0.20 | 0 | 0.97 | 5 | Fixed |
| Stage III or IV | 1.02 | (0.94, 1.10) | 0.65 | 29 | 0.23 | 5 | Fixed |
| Tobacco use: smoker | 1.10 | (0.85, 1.43) | 0.46 | 0 | 0.85 | 3 | Fixed |
| PD-L1 positive | 1.25 | (1.02, 1.52) | 0.03 | 0 | 0.80 | 4 | Fixed |
RR: relative risk; CI: confidence interval; No: number; NPC: nasopharyngeal carcinoma; EBV: Epstein–Barr virus