Table 3. Subgroup analysis of the association between GSTT1 null genotype and HCC risk.
| Polymorphism | Null vs. Present | No. of studies (cases/controls) | Odds ratio | M | Heterogeneity | PE | ||
| OR [95% CI] | POR | I2 (%) | PH | |||||
| GSTT1 | All studies | 21(3378/5400) | 1.38[1.14,1.65] | <0.001 | R | 71.1% | <0.001 | 0.795 |
| subgroup analyses by geographical location | ||||||||
| Southeast regions in mainland China | 16(2454/4019) | 1.51[1.35,1.69] | <0.001 | R | 67.1% | <0.001 | 0.952 | |
| Central regions in mainland China | 1(95/103) | 2.02[1.15,3.56] | 0.020 | F | @ | @ | @ | |
| Taiwan province | 4(829/1278) | 0.94[0.78,1.14] | 0.546 | F | 24.4% | 0.265 | 0.315 | |
| subgroup analyses by number of case | ||||||||
| <100 | 8(561/1022) | 1.34[0.78,2.28] | 0.258 | R | 81.8% | <0.001 | 0.961 | |
| ≥100 | 13(2817/4378) | 1.38[1.16,1.64] | 0.002 | R | 61.0% | <0.001 | 0.560 | |
| subgroup analyses by source of control | ||||||||
| population-based | 17(2845/3725) | 1.32[1.06,1.64] | <0.001 | R | 72.1% | <0.001 | 0.746 | |
| hospital-based | 4(533/1675) | 1.60[1.14,2.26] | 0.007 | R | 63.6% | 0.041 | 0.929 | |
M: model of meta-analysis; R: random-effects model; F: fixed-effects model. PH: P value of heterogeneity test. PE: P value of Egger’s test. POR: P<0.001 replace the P = 0.000 and the P less than 0.001. @: P values could not be calculated.