Table 2. Pooled hypermethylation rates of P16INK4a in LSIL, HSIL and CC specimens.
| Comparison | Studies (N) | Specimens (N) | Heterogeneity | Model a | Methylation rates (%) | |
|---|---|---|---|---|---|---|
| I2(%) | PQ-test | |||||
| LSIL | ||||||
| Total | 14 | 388 | 47 | 0.025 | R | 21.4 (15.0-29.7) |
| Asian | 6 | 86 | 21 | 0.278 | F | 24.6 (16.1-35.5) |
| Caucasian | 5 | 193 | 67 | 0.016 | R | 21.5 (9.8-41.0) |
| Others | 3 | 109 | 59 | 0.088 | R | 13.8 (5.1-31.9) |
| HSIL | ||||||
| Total | 17 | 636 | 82 | < 0.001 | R | 30.9 (21.9-41.7) |
| Asian | 7 | 231 | 81 | < 0.001 | R | 31.9 (18.2-49.7) |
| Caucasian | 7 | 286 | 76 | < 0.001 | R | 27.2 (16.6-41.2) |
| Others | 3 | 119 | 88 | < 0.001 | R | 34.5 (9.9-71.6) |
| CC | ||||||
| Total | 24 | 1439 | 88 | < 0.001 | R | 35.0 (27.6-43.3) |
| Asian | 14 | 941 | 87 | < 0.001 | R | 33.7 (25.5-43.3) |
| Caucasian | 6 | 363 | 85 | 0.006 | R | 38.2 (27.1-50.6) |
| Others | 3 | 135 | 96 | < 0.001 | R | 39.7 (26.7-54.3) |
a
When significant heterogeneity was found (I2≥ 50% or PQ-test ≤ 0.1), the random-effects model (DerSimonian-Laird method) was used to pool the results; otherwise, the fixed-effects model (Mantel-Haenszel method) was applied.
Abbreviations: N, number; LSIL, low-grade squamous intra-epithelial lesion; HSIL, high-grade squamous intra-epithelial lesion; CC, cervical cancer; R, random-effects model.