Table 2.
Meta-relative risk estimates for cancer incidence
| Disease (ICD-10) | # Studies | Study IDs | mSIR (95% CI) | I2 (p value) | τ2 |
|---|---|---|---|---|---|
| All cancer (C00–C97) | 9 | 1, 6, 8, 10, 13, 16, 18, 22, 23 | 1.00 (0.93–1.07) | 91.3 (< 0.001) | 0.010 |
| Buccal cavity and pharynx (C00–C14) | 4 | 10, 13, 18, 23 | 0.87 (0.72–1.02) | 41.8 (0.161) | 0.003 |
| Lip (C00) | 2 | 16, 23 | 0.84 (0.43–1.25) | 0 (0.494) | 0 |
| Esophagus (C15) | 8 | 1, 6, 8, 10, 13, 16, 18, 23 | 1.06 (0.76–1.36) | 65.7 (0.005) | 0.088 |
| Stomach (C16) | 8 | 1, 6, 8, 10, 13, 16, 18, 23 | 1.08 (0.80–1.35) | 71.1 (0.001) | 0.109 |
| Small intestine (C17) | 2 | 1, 23 | 1.65 (0.40–2.90) | 2.2 (0.312) | 0.568 |
| Colon (C18) | 6 | 6, 10, 13, 16, 18, 23 | 1.11 (1.00–1.21) | 19.6 (0.285) | 0 |
| Colorectal combined (C18–C21) | 5 | 1, 10, 13, 22, 23 | 1.08 (1.00–1.16) | 0 (0.539) | 0 |
| Rectum combined (C19–C21) | 8 | 6, 8, 10, 13, 16, 18, 22, 23 | 1.09 (0.99–1.19) | 0 (0.819) | 0 |
| Liver and biliary passages (C22–C24) | 3 | 1, 16, 23 | 0.90 (0.74–1.06) | 0 (0.377) | 0 |
| Liver (C22) | 4 | 1, 13, 18, 23 | 0.81 (0.65–0.98) | 16.6 (0.309) | 0 |
| Gall bladder (C23, C24) | 2 | 1, 23 | 1.16 (0.55–1.78) | 40.2 (0.196) | 0.100 |
| Pancreas (C25) | 8 | 1, 6, 10, 13, 16, 18, 22, 23 | 1.08 (0.88–1.28) | 39.8 (0.114) | 0.021 |
| Larynx (C32) | 5 | 1, 10, 13, 18, 23 | 0.88 (0.66–1.10) | 0 (0.550) | 0 |
| Trachea and lung combined (C33–C34) | 8 | 1, 6, 8, 10, 13, 16, 18, 23 | 0.91 (0.78–1.03) | 87.7 (< 0.001) | 0 |
| Bone (C40, C41) | 2 | 1, 18 | 1.38 (0.47–2.28) | 0 (0.438) | 0.086 |
| Skin combined (C43–C44) | 7 | 6, 10, 13, 16, 18, 22, 23 | 1.16 (0.98–1.35) | 74.2 (0.001) | 0.042 |
| Malignant melanoma of skin (C43) | 6 | 6, 10, 13, 16, 22, 23 | 1.19 (0.89–1.48) | 78.8 (< 0.001) | 0.090 |
| Other malignant skin neoplasms (C44) | 4 | 16, 18, 22, 23 | 1.10 (0.90–1.30) | 63.2 (0.043) | 0.026 |
| Mesothelioma (C45) | 2 | 13, 23 | 1.46 (1.01–1.90) | 0 (0.739) | 0 |
| Soft tissue (C48, C49) | 2 | 16, 23 | 1.20 (0.73–1.67) | 0 (0.699) | 0 |
| Breast (C50) | 4 | 8, 10, 13, 18 | 1.23 (0.27–2.19) | 28.6 (0.240) | 0.513 |
| Genitourinary system (C60–C68) | 2 | 8, 13 | 1.09 (0.99–1.18) | 57.3 (0.126) | 0.003 |
| Male genital (C60–C63) | 2 | 8, 13 | 1.10 (0.92–1.28) | 85.5 (0.009) | 0.016 |
| Prostate (C61) | 9 | 1, 6, 8, 10, 13, 16, 18, 22, 23 | 1.10 (0.97–1.22) | 75.0 (< 0.001) | 0.025 |
| Testis (C62) | 5 | 6, 13, 18, 22, 23 | 1.26 (0.87–1.65) | 77.0 (0.002) | 0.141 |
| Urinary tract (C64–C68) | 3 | 8, 10, 13 | 1.07 (0.92–1.22) | 41.4 (0.182) | 0.007 |
| Kidney combined (C64–C66) | 8 | 1, 6, 8, 10, 13, 16, 18, 23 | 0.98 (0.75–1.20) | 62.6 (0.009) | 0.053 |
| Bladder combined (C67–C68) | 7 | 1, 6, 8, 10, 13, 18, 22 | 1.14 (1.04–1.23) | 0 (0.592) | 0 |
| Bladder (C67) | 6 | 1, 6, 10, 13, 18, 22 | 1.18 (1.01–1.34) | 0 (0.492) | 0.005 |
| Eye (C69) | 2 | 8, 18 | 3.08 (0.00–6.62) | 0 (0.461) | 5.255 |
| Brain combined (C70–C72) | 7 | 1, 6, 10, 13, 16, 18, 23 | 0.81 (0.65–0.98) | 6.2 (0.380) | 0 |
| Thyroid (C73) | 5 | 1, 10, 13, 18, 23 | 1.26 (0.98–1.54) | 0 (0.623) | 0.011 |
| Lymphohematopoietic (C81–C96) | 4 | 1, 13, 16, 18 | 0.90 (0.63–1.17) | 76.1 (0.006) | 0.055 |
| Hodgkin's disease (C81) | 4 | 10, 13, 16, 18 | 0.84 (0.44–1.24) | 0 (0.906) | 0 |
| Non-Hodgkin lymphoma combined (C82–C85) | 6 | 1, 10, 13, 16, 18, 22 | 1.05 (0.83–1.28) | 0 (0.484) | 0.018 |
| Multiple myeloma (C90) | 4 | 10, 13, 16, 23 | 1.11 (0.85–1.38) | 0 (0.888) | 0 |
| Leukemia (C91–C95) | 9 | 1, 6, 8, 10, 13, 16, 18, 20, 23 | 1.05 (0.66–1.45) | 35.4 (0.135) | 0.248 |
Statistically significant results are marked in bold
Study IDs IDs of included studies in this meta-analysis as depicted in Table 1, mSIR meta-relative standardized incidence ratios assessed with an inverse-variance random-effects meta-analysis with Paule–Mandel heterogeneity variance estimator τ2, CI confidence interval, p value p value of heterogeneity test