Table 3.
Minimally1 adjusted relative risks (RR) and 95% confidence intervals (CI) for the association of circulating levels of cadmium with breast cancer risk in a meta-analysis of in three studies with prospective blood collection
| Cadmium (μg/L) | ||||||
|---|---|---|---|---|---|---|
| 0–0.49 | 0.50–0.99 | 1.00–1.49 | 1.50–1.99 | 2.00 + | Continuous | |
| Cancer Prevention Study-II Lifelink (CPS-II) | ||||||
| Case N | 310 | 395 | 78 | 23 | 10 | 816 |
| Control N | 334 | 365 | 87 | 17 | 13 | 816 |
| RR (95% CI) | 1.00 | 1.16 (0.94–1.43) | 0.96 (0.68–1.35) | 1.40 (0.73–2.7) | 0.80 (0.35–1.87) | 1.01 (0.76–1.34) |
| p for trend | 0.96 | |||||
| European Prospective Investigation into Cancer and Nutrition - Italy (EPIC-Italy) | ||||||
| Case N | 88 | 119 | 45 | 23 | 19 | 294 |
| Control N | 75 | 118 | 48 | 19 | 32 | 292 |
| RR (95% CI) | 1.00 | 0.87 (0.58–1.32) | 0.76 (0.45–1.30) | 1.00 (0.50–2.04) | 0.52 (0.26–1.00) | 0.80 (0.61–1.03) |
| p for trend | 0.08 | |||||
| Northern Sweden Health and Disease Study (NSHDS) | ||||||
| Case N | 145 | 110 | 24 | 16 | 30 | 325 |
| Control N | 126 | 106 | 26 | 23 | 44 | 325 |
| RR (95% CI) | 1.00 | 1.03 (0.62–1.73) | 0.67 (0.28–1.58) | 0.42 (0.16–1.05) | 0.56 (0.26–1.17) | 0.73 (0.54–0.97) |
| p for trend | 0.026 | |||||
| Meta-analysis | ||||||
| Case N | 543 | 624 | 147 | 62 | 59 | 1435 |
| Control N | 535 | 589 | 161 | 59 | 89 | 1433 |
| RR (95% CI) | 1.00 | 1.09 (0.91–1.30) | 0.87 (0.66–1.15) | 0.90 (0.48–1.71) | 0.59 (0.39–0.91) | 0.84 (0.69–1.01) |
| I2 | NA | 0.0% | 0.0% | 52.9% | 0.0% | 27% |
1
Models were adjusted for matching factors, which included race (CPS-II), birthdate (within 6 months in CPS-II and within 2.5 years in EPIC-Italy and NSHDS), menopausal status (NSHDS, EPIC-Italy), study center (EPIC-Italy) and blood draw date (within 6 months in CPS-II and within the same year in EPIC-Italy and NSHDS).