Table 2.
Subgroup analysis of correlation between polymorphism of XPD 751 and CRC risk
| Comparisons | Number of studies | Odds ratio
|
Test of heterogeneity
|
|||
|---|---|---|---|---|---|---|
| OR (95% CI) | P-value | Z-value | I2 (%) | P-value | ||
| Asians | ||||||
| Gln-Gln versus Lys-Lys | 4 | 1.05 (0.72–1.53) | 0.807 | 0.24 | 0.0 | 0.426 |
| Lys-Gln versus Lys-Lys | 4 | 1.12 (0.95–1.33) | 0.181 | 1.34 | 0.8 | 0.930 |
| Lys-Gln + Gln-Gln versus Lys-Lys | 4 | 0.74 (0.33–1.67) | 0.467 | 0.73 | 94.9 | <0.001 |
| Caucasians | ||||||
| Gln-Gln versus Lys-Lys | 6 | 1.07 (0.89–1.28) | 0.497 | 0.68 | 49.8 | 0.076 |
| Lys-Gln versus Lys-Lys | 6 | 1.02 (0.88–1.18) | 0.788 | 0.27 | 0.0 | 0.509 |
| Lys-Gln + Gln-Gln versus Lys-Lys | 7 | 1.05 (0.94–1.17) | 0.424 | 0.80 | 85.3 | <0.001 |
| PB | ||||||
| Gln-Gln versus Lys-Lys | 3 | 1.12 (0.87–1.43) | 0.369 | 0.90 | 3.5 | 0.355 |
| Lys-Gln versus Lys-Lys | 3 | 1.00 (0.84–1.18) | 0.969 | 0.04 | 0.0 | 0.794 |
| Lys-Gln + Gln-Gln versus Lys-Lys | 4 | 1.05 (0.93–1.20) | 0.423 | 0.80 | 0.0 | 0.657 |
| HB | ||||||
| Gln-Gln versus Lys-Lys | 7 | 1.02 (0.81–1.28) | 0.876 | 0.16 | 41.4 | 0.115 |
| Lys-Gln versus Lys-Lys | 7 | 1.11 (0.96–1.28) | 0.154 | 1.43 | 0.0 | 0.745 |
| Lys-Gln + Gln-Gln versus Lys-Lys | 7 | 0.84 (0.52–1.35) | 0.475 | 0.71 | 90.6 | <0.001 |
Abbreviations: CI, confidence interval; CRC, colorectal cancer; OR, odds ratio; HB, hospital-based; PB, population-based; XPD, xeroderma pigmentosum complementary group D.