Data source | Study type | Sampling | Cases | Control | Exposed | Non-exposed | |
Ghorbani et al. 2015 [14] | CR | Case-control | 347 | 300 | - | - | |
Lowry et al. 2014 [12] | SEER | Case-control | Population-based | 715 | 376 | - | - |
Li et al. 2009 [11] | SEER | Case-control | Population-based | 4568 | 4678 | - | - |
Mathes et al. 2008 [13] | CSS | Case-control | Population-based | 1938 | 1474 | - | - |
Li et al. 2010 [10] | WHI | Cohort | Population-based | - | - | 10464 | 80652 |
Winter et al. 2013 [15] | WHS | Cohort | Population-based | - | - | 7318 | 32378 |