Table 1. Characteristics of studies included in this meta-analysis.
| Author | Year | Country | Sample size | Lauren differentiation (diffuse, %) | WHO differentiation (G3, %) | T1-2 (%) | N0 (%) | Location (U, %) | MSI | EBV (+) (ISH) | ARID1A (−) (%) | OS HR-E | HR (95% CI) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Abe | 2012 | Japan | 250 | 53.3% | NA | NA | NA | 27.9% | 14.4% (I) | 3.2% | 11.0% | SC | 2.35 (1.39, 3.98) | |
| Wang | 2012 | China | 224 | NA | 78.6% | 26.4% | 40.2% | NA | NA | NA | 51.3% | HR | 1.64 (1.05, 2.54) | |
| Wu | 2012 | China | 166 | NA | 65.7% | 31.3% | 18.7% | NA | NA | NA | 24.1% | RR | 1.91 (1.27, 2.87) | |
| Yan | 2014 | China | 176 | NA | 51.7% | 30.1% | 33.0% | NA | NA | NA | 25.0% | HR | 1.98 (1.10, 3.57) | |
| Li | 2014 | China | 90 | NA | 61.1% | 15.6% | 24.4% | 50.0% | NA | NA | 70.0% | SC | 2.13 (0.89, 5.08) | |
| Wiegand (Toronto) | 2014 | Canada | 80 | 25.0% | 57.5% | 22.5% | 40.0% | NA | 21.3% (I) | 2.5% | 20.0% | HR | 6.54 (2.09, 22.38) | |
| Wiegand (Vancouver) | 2014 | Canada | 173 | 21.4% | 51.5% | 10.4% | 24.0% | NA | 14.5% (I) | 3.5% | 22.5% | HR | 1.04 (0.61, 1.71) | |
| Dou | 2015 | China | 103 | 37.9% | 37.9% | 42.7% | 54.4% | NA | NA | NA | 65.0% | RR | 1.59 (1.06, 2.33 ) | |
| Han | 2015 | Korea | 417 | 40.5% | 36.9% | 26.9% | NA | NA | 8.2% (P) | 7.3% | 21.1% | SC | 1.49 (0.93, 2.39) | |
| Ibarrola- Villava | 2015 | Spain | 66 | 36.4% | 30.3% | NA | NA | 30.3% | 15.2% (P) | NA | 27.0% | SC | 0.69 (0.31, 1.55) | |
| Inada | 2015 | Japan | 489 | NA | 60.5% | NA | 24.1% | NA | 7.8% (I) | NA | 39.6% | HR | 1.36 (1.01, 1.84) | |
| Kim | 2015 | Korea | 191 | 37.7% | 64.4% | 50.3% | 45.5% | 13.1% | 19.9% (I) | NA | 32.5% | SC | 1.41 (0.74, 2.68) | |
| Lee | 2015 | Korea | 275 | 46.9% | NA | 56.7% | 47.3% | 15.3% | 6.4% (P) | NA | 8.0% | SC | 2.70 (0.50, 14.50) | |
| Kim | 2016 | Korea | 350 | 32.3% | 58.8% | 33.7% | 31.1% | 20.0% | 18.9% (I) | 10% | 18.6% | HR | 1.66 (1.13, 2.46) | |
| Zhao | 2016 | China | 133 | 62.4% | 70.7% | 12.0% | 18.8% | NA | NA | NA | 42.1% | HR | 1.69 (1.06, 2.67) | |
NA: Not available; U: Upper third part of stomach; MSI: Microsatellite instability; I: Immunohistochemistry of mismatch repair proteins; P: Polymerase chain reaction and electrophoresis of DNA; EBV: Epstein-Barr virus; ISH: In situ hybridization; OS: Overall Survival; HR-E: HR Estimated; SC: Survival curve; HR: Hazard ratio; RR: Relative risk; CI: Confidence interval.