Variables | No. of studies | Pooled risk ratio (95% CI) | I 2 statistic, % | χ2 P value for heterogeneity | Analytical model |
---|---|---|---|---|---|
Publication year | |||||
Before 2010 | 1.92 (1.30–2.83) | 94 | <0.001 | REM | |
After 2011 | 1.58 (1.15–2.18) | 89 | <0.001 | REM | |
Geographic location | |||||
Asia | 2.21 (1.66–2.94) | 86 | <0.001 | REM | |
Europe | 1.26 (1.06–1.51) | 70 | 0.010 | REM | |
Europe (exclude the lowest effect size [28]) | 1.29 (1.20–1.39) | 22 | 0.280 | FEM | |
Recruited period | |||||
Before 2000 | 4 [17b, 22, 23 b, 27] | 1.29 (1.20–1.39) | 10 | 0.340 | FEM |
2000 to 2006 | 2.08 (1.40–3.08) | 91 | <0.001 | REM | |
After 2006 | 2a [11] | 2.77 (2.22–3.47) | 0 | 0.700 | FEM |
Sample size (n, median) | |||||
≥452 | 1.38 (1.07–1.78) | 90 | <0.001 | REM | |
<452 | 2.35 (1.45–3.81) | 90 | <0.001 | REM | |
≥1000 | 1.27 (1.17–1.38) | 0 | 0.420 | FEM | |
Tissue processing | |||||
TMA | 1.49 (1.13–1.95) | 90 | <0.001 | REM | |
Whole slide section | 2.12 (1.49–3.04) | 89 | <0.001 | REM | |
IHC antibodies | |||||
NCH-38 antibody | 2.49 (1.96–3.15) | 64 | 0.090 | REM | |
HECD-1 antibody | 1.50 (0.91–2.48) | 71 | 0.060 | REM | |
HECD-1 antibody | 1.27 (1.15–1.40) | 71 | 0.060 | FEM | |
4A2C7 antibody | 2.29 (1.00–5.25) | 94 | <0.001 | REM | |
4A2C7 antibody (only whole slide section) | 2a [24] | 3.38 (2.47–4.62) | 38 | 0.210 | FEM |
Cutoff | |||||
10% | 1.85 (1.15–2.98) | 92 | <0.001 | REM | |
30 and 50% | 1.72 (1.02–2.90) | 93 | <0.001 | REM | |
100 H-score | 1.27 (1.17–1.38) | 0 | 0.420 | FEM | |
Prevalence of E-cad expression (%, median) | |||||
>64% | 2.02 (1.22–3.36) | 87 | <0.001 | REM | |
>64% (exclude the highest prevalence [28]) | 2.74 (2.31–3.25) | 40 | 0.150 | FEM | |
≤64% | 1.47 (1.21–1.79) | 88 | <0.001 | REM | |
≤50% | 1.27 (1.18–1.36) | 0 | 0.880 | FEM | |
NOS score | |||||
7 | 1.53 (1.20–1.96) | 90 | <0.001 | REM | |
5 and 6 | 1.82 (1.21–2.72) | 90 | <0.001 | REM |