Table 2.
Subgroup analysis of pooled HR of OS by various factors with elevated 8-OHdG expression
| Subgroup analysis | No. of studies | No. of patients | Pooled HR (95%CI) | Meta regression (p -value) | Heterogeneity | |
|---|---|---|---|---|---|---|
| I2 | p -value | |||||
| Race | ||||||
| Caucasoid | 12 | 1129 | 1.962 [1.341–2.870] | 0.907 | 66.6% | 0.001 |
| Mongoloid | 5 | 467 | 1.862 [1.117–3.104] | – | 80.2% | < 0.001 |
| Cancer types | ||||||
| Hepatocellular carcinoma | 2 | 156 | 2.853 [0.673–12.089] | 0.727 | 84.2% | 0.012 |
| Ovarian carcinoma | 6 | 424 | 1.867 [1.190–2.930] | 0.464 | 58.0% | 0.036 |
| Colorectal cancer | 4 | 330 | 1.637 [0.850–3.153] | 0.352 | 71.5% | 0.014 |
| Esophageal cancer | 1 | 144 | 3.400 [2.055–5.624] | 0.982 | – | – |
| Nonsmall-Cell Lung cancer | 1 | 99 | 3.330 [1.588–6.982] | – | – | – |
| Melanoma | 1 | 46 | 1.470 [1.019–2.121] | 0.367 | – | – |
| Breast cancer | 1 | 145 | 0.100 [0.017–0.583] | 0.019 | – | – |
| Bladder cancer | 1 | 252 | 3.130 [1.298–7.548] | 0.950 | – | – |
| Detection method of 8-OHdG | ||||||
| IHC | 12 | 1157 | 1.787 [1.246–2.563] | 0.646 | 74.1% | < 0.001 |
| ELISA | 4 | 360 | 2.386 [1.167–4.881] | 0.947 | 71.0% | 0.016 |
| LCEC | 1 | 79 | 2.510 [1.018–6.187] | – | – | |
| Sample classification | ||||||
| Tissue | 14 | 1412 | 1.792 [1.307–2.458] | – | 73.6% | < 0.001 |
| Plasma or urine | 3 | 268 | 3.042 [1.676–5.519] | 0.006 | 0.0% | 0.856 |
| Detection location of 8-OHdG | ||||||
| Nuclei | 10 | 1019 | 1.927 [1.321–2.810] | 0.596 | 71.5% | < 0.001 |
| Cytoplasm | 1 | 138 | 0.759 [0.454–1.268] | 0.118 | – | – |
| Not mentioned | 6 | 439 | 2.345 [1.429–3.848] | – | 57.6% | 0.038 |
| research quality | ||||||
| NOS score ≥ 7 | 5 | 499 | 1.658 [1.002–2.743] | 0.526 | 82.7% | < 0.001 |
| NOS score < 7 | 12 | 1097 | 2.104 [1.456–3.040] | – | 60.6% | 0.003 |