Table 2.
Basic information of Mendelian randomization studies presented in Table 1
| Cancer | First author, Year | Data source | No. of SNPs | % of variance explained | 3 basic assumptions assesseda |
||
|---|---|---|---|---|---|---|---|
| Relevance | Independence | Exclusion restriction | |||||
| Breast | |||||||
| Early life | Gao, et al., 2016 (9) | DRIVE | 15 | 2.0 | √ | √b | √ |
| Adult | Guo, et al., 2016 (10) | BCAC, DRIVE | 84 | 1.2 | √ | √ | × |
| Ovary | |||||||
| Early life | Gao, et al., 2016 (9) | FOCI | 15 | 2.0 | √ | √b | √ |
| Adult | Dixon, et al., 2016 (30) | OCAC | 87 | 1.6 | √ | √ | √ |
| Colorectum | |||||||
| Early life | Jarvis, et al., 2016 (37) | CCFR1, CCFR2, COIN, FINLAND, UK1, Scotland1, VQ58 | 9 | Not reported | √ | √c | √ |
| Adult | Bull et al., 2020 (38) | GECCO, CORECT, C-CFR | 312 (185 for women, 152 for men) | 0.3-5.04 | √ | × | √ |
| Endometrium, adult | Painter et al., 2016 (34) | ECAC | 77 | 1.0 | √ (but not reported F-statistics/r-square) | √ | √ |
| Esophageal adenocarcinoma, adult | Thrift et al., 2014 (44) | BEAGSS | 29 | 0.16 kg/m2 | √ | √ | √ |
| Pancreas, adult | Carreras-Torres et al. 2017 (46) | PanScan, PanC4 | 96 | 2.7 | √ | √ | √ |
| Kidney, adult | Johansson et al., 2019 (64) | IARC-1, NCI-1, MDA, UK | 709 | 9.5 | √ | × | √ |
| Lung, adult | Zhou et al., 2020 (56) | TRICL, ILCCO | 842 | 7.3 | √ | √ (smoking) | √ |
Relevance assumption: the genetic variants associate with the risk factor of interest; independence assumption: the genetic variants do not share common causes with the outcome; exclusion restriction: the genetic variants affect the outcome only through their effect on the risk factor of interest. BCAC = Breast Cancer Association Consortium; BEAGSS = Barrett’s and Esophageal Adenocarcinoma Genetic Susceptibility Study; C-CFR = Colon-Cancer Family Registry; CORECT = Colorectal Transdisciplinary Study; DRIVE = Discovery, Biology and Risk of Inherited Variants in Breast Cancer Project; ECAC = Endometrial Cancer Association Consortium; FOCI = Follow-up of Ovarian Cancer Genetic Association and Interaction Studies; GECCO = Genetics and Epidemiology of Colorectal Cancer Consortium; IARC = International Agency for Research on Cancer; ILCCO = International Lung Cancer Consortium; MDA = MD Anderson Cancer Center; NCI = US National Cancer Institute; OCAC = Ovarian Cancer Association Consortium; PanScan = Pancreatic Cancer Cohort Consortium; PanC4 = Pancreatic Cancer Case-Control Consortium; TRICL = Transdisciplinary Research in Cancer of the Lung; UK = United Kingdom cancer research centers.
Only mentioned that there was no confounding by population stratification without showing associations between SNPs and other confounders.
Only discussed the plausibility without showing associations between SNPs and confounders.