Table 4.
Comparison of the results with number of included individual studies of our study and the largest meta-analysis.
| Type of Cancer | Randomized Controlled Trials | Observational Studies | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Our Study | Largest Meta-Analysis * | Our Study | Largest Meta-Analysis * | |||||||||
| No. of Study | Random Effects (RR 95% CI) | No. of Study | Random Effects (RR 95% CI) | No. of Study | Random Effects (RR 95% CI) | No. of Study | Random Effects (RR 95% CI) | |||||
| Bladder cancer | 3 | 0.84 (0.64–1.09) | 3 | 0.83 (0.64–1.09) | 10 | 1.11 (0.97–1.26) | 10 | 1.11 (0.97–1.26) | ||||
| Breast cancer | 12 | 1.00 (0.80–1.25) | 7 | 1.19 (0.81–1.73) | 50 | 0.90 (0.84–0.96) | 21 | 0.99 (0.94–1.04) | ||||
| Colorectal cancer | 13 | 0.92 (0.81–1.05) | 11 | 0.96 (0.85–1.08) | 46 | 0.92 (0.88–0.95) | 32 | 0.92 (0.87–0.96) | ||||
| Endometrial cancer | 2 | 0.72 (0.19–2.67) | 2 | 0.72 (0.19–2.67) | 13 | 0.94 (0.82–1.07) | 13 | 0.94 (0.82–1.07) | ||||
| Esophageal cancer | 1 | 0.98 (0.69–1.40) | - | - | 26 | 0.69 (0.62–0.76) | 10 | 0.59 (0.50–0.68) | ||||
| Gastric cancer | 3 | 0.84 (0.61–1.14) | 3 | 0.84 (0.61–1.14) | 13 | 0.71 (0.56–0.90) | 9 | 0.70 (0.53–0.93) | ||||
| Gynecological cancer | 6 | 1.03 (0.65–1.63) | 6 | 1.03 (0.65–1.63) | 17 | 0.88 (0.76–1.01) | 17 | 0.88 (0.76–1.01) | ||||
| Hematological cancer | 8 | 0.96 (0.78–1.17) | 6 | 0.92 (0.78–1.09) | 26 | 0.88 (0.81–0.97) | 22 | 0.88 (0.80–0.98) | ||||
| Kidney cancer | 2 | 1.01 (0.57–1.78) | 2 | 1.01 (0.57–1.78) | 9 | 0.90 (0.69–1.18) | 9 | 0.90 (0.69–1.18) | ||||
| Leukemia | - | - | - | - | 9 | 0.85 (0.74–0.98) | 9 | 0.85 (0.74–0.98) | ||||
| Liver cancer | 3 | 0.96 (0.62–1.49) | - | - | 24 | 0.57 (0.50–0.65) | 6 | 0.58 (0.46–0.74) | ||||
| Lung cancer | 9 | 0.95 (0.85–1.05) | 7 | 0.95 (0.84–1.09) | 24 | 0.87 (0.77–0.99) | 15 | 0.88 (0.75–1.03) | ||||
| Lymphoma | - | - | - | - | 16 | 0.85 (0.73–0.99) | 13 | 0.83 (0.69–0.99) | ||||
| Melanoma | 13 | 1.06 (0.90–1.25) | 9 | 0.92 (0.62–1.36) | 11 | 0.92 (0.84–1.02) | - | - | ||||
| Myeloma | - | - | - | - | 5 | 0.89 (0.53–1.51) | 5 | 0.89 (0.53–1.51) | ||||
| Pancreatic cancer | 3 | 0.99 (0.44–2.21) | 3 | 0.99 (0.44–2.21) | 17 | 0.89 (0.74–1.07) | 15 | 0.88 (0.73–1.07) | ||||
| Prostate cancer | 7 | 1.06 (0.93–1.20) | 6 | 1.06 (0.93–1.20) | 57 | 0.93 (0.88–0.98) | 27 | 0.90 (0.80–1.01) | ||||
| Non-melanoma skin cancer | 8 | 1.07 (0.86–1.33) | 7 | 1.09 (0.85–1.39) | 9 | 1.08 (1.00–1.18) | 5 | 1.11 (1.02–1.22) | ||||
RR: Relative risk; CI: Confidence interval. * Meta-analysis including largest number of individual studies.