Table 2.
Subgroup analysis of the pooled HRs for OS.
| Subgroup analysis | Number of studies | Number of patients | HR (95% CI) | P value | Heterogeneity | |
|---|---|---|---|---|---|---|
| I2 | P value | |||||
| Overall | 15 | 1047 | 1.962 (1.630-2.362) | p <0.001 | 34.9% | 0.09 |
| Expression in cancer tissue | ||||||
| High | 14 | 919 | 2.151 (1.777-2.603) | p <0.001 | 0.0% | 0.971 |
| Low | 1 | 128 | 0.400 (0.181-0.884) | 0.024 | NA | NA |
| Cancer type | ||||||
| Digestive system | 6 | 431 | 2.124 (1.629-2.770) | p <0.001 | 0.0% | 0.671 |
| Non-digesstive system | 9 | 616 | 1.837 (1.230-2.744) | 0.003 | 54.6% | 0.024 |
| Analysis method | ||||||
| Multivariate analysis | 6 | 415 | 2.452 (1.816-3.310) | p <0.001 | 0.0% | 0.653 |
| Univariate analysis | 9 | 632 | 1.709 (1.350-2.164) | p <0.001 | 45.8% | 0.064 |
| NOS score | ||||||
| ≥7 | 11 | 791 | 1.803 (1.449-2.244) | p <0.001 | 39.2% | 0.088 |
| <7 | 4 | 256 | 2.437 (1.716-3.461) | p <0.001 | 0.5% | 0.389 |