Table 2 Results of subgroup and meta-regression analyses
Subgroup | Studies | HR (95%CI) | P-value | Heterogeneity (I2) | Pheterogeneity | Meta-regression (P-value) |
|---|---|---|---|---|---|---|
Ethnicity |  |  |  |  |  | P = 0.776 |
 Asian | 9 | 1.46 (1.25–1.71) | P < 0.001 | 91.5% | P < 0.001 |  |
 Non-Asian | 3 | 1.43 (0.92–2.23) | P = 0.11 | 74.1% | P = 0.021 |  |
Cancer type |  |  |  |  |  | P = 0.189 |
 Gastric cancer | 7 | 1.25 (1.10–1.40) | P = 0.006 | 86.4% | P < 0.001 |  |
 Colorectal cancer | 4 | 2.71 (1.33–5.54) | P < 0.001 | 84.2% | P < 0.001 |  |
Sample source |  |  |  |  |  | P = 0.851 |
 Blood | 5 | 1.65 (1.14–2.37) | P = 0.008 | 87.1% | P < 0.001 |  |
 Tissue | 7 | 1.29 (1.11–1.50) | P = 0.001 | 90.2% | P < 0.001 |  |
Sample size |  |  |  |  |  | P = 0.271 |
 Large(>median) | 5 | 2.37 (1.29–4.33) | P = 0.005 | 86.2% | P < 0.001 |  |
 Small(<median) | 6 | 1.25 (1.10–1.43) | P = 0.001 | 80.4% | P < 0.001 |  |