Table 3.
Summary risk estimates of the association between hormone replacement therapy and ovarian cancer by histologic subtype.
| Histologic subtype of ovarian cancer | Subgroup | No. of studies | Pooled RR(95% CI) | I2 (%) | Pheterogeneity |
|---|---|---|---|---|---|
| Serous tumor | All studies | 12 | 1.50 (1.35–1.68) | 27.5 | 0.175 |
| Study design | |||||
| Cohort studies | 3 | 1.64 (1.46–1.85) | 0.0 | 0.998 | |
| Case control studies | 9 | 1.42 (1.20–1.67) | 33.6 | 0.149 | |
| Continent | |||||
| North America | 6 | 1.61 (1.38–1.88) | 0.0 | 0.578 | |
| Europe | 5 | 1.51 (1.36–1.68) | 2.7 | 0.391 | |
| Australia | 1 | 0.71 (0.40–1.27) | NA | NA | |
| Hormones types | |||||
| HRT | 9 | 1.48 (1.29–1.70) | 38.8 | 0.109 | |
| ERT | 3 | 1.54 (1.25–1.89) | 4.3 | 0.352 | |
| Mucinous | All studies | 9 | 0.66 (0.52–0.85) | 0.0 | 0.553 |
| tumor | Study design | ||||
| Cohort studies | 2 | 0.71 (0.50–1.01) | 0.0 | 0.495 | |
| Case control studies | 7 | 0.62 (0.44–0.89) | 1.9 | 0.410 | |
| Continent | |||||
| North America | 4 | 0.79 (0.43–1.44) | 0.0 | 0.666 | |
| Europe | 4 | 0.62 (0.40–0.94) | 38.8 | 0.179 | |
| Australia | 1 | 0.67 (0.28–1.62) | NA | NA | |
| Hormones types | |||||
| HRT | 6 | 0.74 (0.58–0.97) | 0.0 | 0.900 | |
| ERT | 3 | 0.41 (0.23–0.73) | 0.0 | 0.383 | |
| Endometrioid | All studies | 10 | 1.48 (1.13–1.94) | 51.8 | 0.028 |
| tumor | Study design | ||||
| Cohort studies | 3 | 1.88 (1.49–2.36) | 0.0 | 0.789 | |
| Case control studies | 7 | 1.25 (0.86–1.82) | 53.1 | 0.046 | |
| Continent | |||||
| North America | 6 | 1.32 (0.78–2.23) | 66.2 | 0.011 | |
| Europe | 4 | 1.61 (1.32–1.97) | 5.5 | 0.365 | |
| Hormones types | |||||
| HRT | 7 | 1.40 (0.99–1.98) | 60.2 | 0.020 | |
| ERT | 3 | 1.68 (0.97–2.91) | 38.6 | 0.196 | |
| Clear cell | All studies | 5 | 0.94 (0.65–1.36) | 0.0 | 0.689 |
| tumor | Study design | ||||
| Cohort studies | 2 | 1.06 (0.50–2.23) | 47.3 | 0.168 | |
| Case control studies | 3 | 0.95 (0.48–1.90) | 0.0 | 0.837 | |
| Continent | |||||
| North America | 3 | 1.36 (0.70–2.64) | 0.0 | 0.776 | |
| Europe | 2 | 0.80 (0.51–1.24) | 0.0 | 0.853 | |
| Hormones types | |||||
| HRT | 4 | 0.97 (0.66–1.44) | 0.0 | 0.567 | |
| ERT | 1 | 0.72 (0.23–2.27) | NA | NA | |
| Other type of | All studies | 5 | 1.21 (0.91–1.61) | 39.0 | 0.161 |
| ovarian cancer | Study design | ||||
| Cohort studies | 1 | 1.53 (1.10–2.12) | NA | NA | |
| Case control studies | 4 | 1.08 (0.80–1.45) | 16.2 | 0.311 | |
| Continent | |||||
| North America | 3 | 1.44 (1.09–1.92) | 0.0 | 0.747 | |
| Europe | 2 | 1.07 (0.62–1.84) | 69.6 | 0.070 | |
| Hormones types | |||||
| HRT | 4 | 1.44 (1.13–1.84) | 0.0 | 0.900 | |
| ERT | 1 | 0.82 (0.56–1.20) | NA | NA |
RR, relative risk; CI, confidence interval.