From: Systematic review of the relation between smokeless tobacco and cancer in Europe and North America
 | ST use |  |  | RR/OR | ||||
---|---|---|---|---|---|---|---|---|
Sourcea | Typeb | Exposurec | Smoking | Sex | Id. | Casesd | Estimate (95%CI) | Adjustment factorse |
Case-control studies | Â | Â | Â | Â | Â | Â | Â | Â |
Wynder et al. 1957 [40] | Â | Â | Â | Â | Â | Â | Â | Â |
- larynx cancer | Chew | Ever | Any | M | 1 | NA | no associationf | none |
Vincent and Marchetta 1963 [45] | Â | Â | Â | Â | Â | Â | Â | Â |
- larynx cancer | Snuff | Use | Any | M | 2 | 5 | 1.81 (0.33–9.97) | none |
Williams and Horm 1977 [55] | Â | Â | Â | Â | Â | Â | Â | Â |
- larynx cancer | ST | Ever | Any | M | 3 | 16 | 2.01 (1.15–3.51)g | age, race, smok |
Wynder and Stellman 1977 [56] | Â | Â | Â | Â | Â | Â | Â | Â |
- larynx cancer | Chew | Ever | Any | M | 4 | 46 | 1.35 (0.96–1.89)g | none |
 | Snuff |  |  |  | 5 | 15 | 1.46 (0.82–2.57)g | none |
 | ST |  |  |  | 6 | 61 | 1.40 (1.04–1.89)h | none |
Engzell et al. 1978 [57] | Â | Â | Â | Â | Â | Â | Â | Â |
- nasal cancer | Snuff | Use | Any | M | 7 | NA | no association | none |
Brinton et al. 1984 [64] | Â | Â | Â | Â | Â | Â | Â | Â |
- nasal cancer | Chew | Use | Any | M+F | 8 | 15 | 0.74 (0.40–1.50) | sex |
 | Snuff |  |  |  | 9 | 23 | 1.47 (0.80–2.80) |  |
 | ST |  |  |  | 10 | 38 | 1.08 (0.68–1.70)h | none |
Stockwell and Lyman 1986 [70] | Â | Â | Â | Â | Â | Â | Â | Â |
- nasal cancer | ST | Ever | Any | M+F | 11 | 1 | 2.93 (0.40–21.66)g | none |
- larynx cancer | ST | Ever | Any | M+F | 12 | 6 | 2.02 (0.84–4.86)g | none |
Young et al. 1986 [71] | Â | Â | Â | Â | Â | Â | Â | Â |
- larynx cancer | ST | Ever | Any | M | 13 | NA | no association | none |
Lewin et al. 1998 [102] | Â | Â | Â | Â | Â | Â | Â | Â |
- larynx cancer | Snuff | Current | Any | M | 14 | 15 | 1.00 (0.50–1.90) | age, alc, res, smok |
 |  | Former |  |  | 15 | 9 | 0.80 (0.40–1.70) |  |
 |  | Ever |  |  | 16 | 24 | 0.90 (0.50–1.50) |  |