Table 2.
Variable | No.a | Cases/controls | CC versus TT | CT versus TT | CC/CT versus TT | CC versus CT/TT | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
OR (95 % CI) | P b | P | OR (95 % CI) | P b | P | OR (95 % CI) | P b | P | OR (95 % CI) | P b | P | |||
Total | 22 | 5,903/8,132 | 0.96 [0.86, 1.09] | 0.10 | 0.55 | 1.07 [0.86, 1.32] | 0.00c | 0.56 | 1.03 [0.85, 1.25] | 0.00c | 0.76 | 0.93 [0.80, 1.08] | 0.01c | 0.36 |
Ethnicities | ||||||||||||||
Occident | 11 | 3,961/5,460 | 0.98 [0.87, 1.1] | 0.11 | 0.72 | 1.10 [0.89, 1.37] | 0.00c | 0.38 | 1.06 [0.88, 1.28] | 0.00c | 0.54 | 0.95 [0.83, 1.09] | 0.07c | 0.45 |
Asian | 9 | 1,772/2,378 | 0.78 [0.36, 1.7] | 0.15 | 0.53 | 0.87 [0.40, 1.92] | 0.00c | 0.74 | 0.91 [0.42, 1.95] | 0.00c | 0.81 | 1.60 [0.87, 2.93] | 0.31 | 0.13 |
African | 1 | 96/222 | 1.16 [0.56, 2.39] | NEd | 0.70 | 1.25 [0.56, 2.39] | NEd | 0.54 | 1.21 [0.62, 2.35] | NEd | 0.58 | 0.98 [0.59, 1.63] | NEd | 0.94 |
Mixed | 1 | 74/72 | 0.44 [0.17, 1.11] | NEd | 0.53 | 1.67 [0.73, 3.80] | NEd | 0.22 | 1.04 [0.48, 2.23] | NEd | 0.93 | 0.32 [0.16, 0.67] | NEd | 0.02 |
Cancer types | ||||||||||||||
Colorectal cancer | 7 | 2,666/4,022 | 1.06 [0.9, 1.25] | 0.37 | 0.48 | 1.08 [0.93, 1.26] | 0.67 | 0.32 | 1.07 [0.93, 1.23] | 0.78 | 0.37 | 0.93 [0.74, 1.17] | 0.05c | 0.53 |
Gastric cancer | 3 | 623/803 | NEd | 1.65 [0.30, 1.42] | 0.97 | 0.28 | 1.65 [0.30, 1.42] | 0.97 | 0.28 | NEd | ||||
Head and neck cancer | 2 | 1,069/1,331 | 0.80 [0.63, 1.01] | 0.33 | 0.06 | 0.73 [0.59, 0.90] | 0.34 | 0.003 | 1.75 [0.62, 0.92] | 0.31 | 0.005 | 1.00 [0.84, 1.20] | 0.67 | 0.98 |
Hepatocellular cancer | 3 | 304/578 | 1.16 [0.56, 2.39] | NEd | 0.70 | 1.18 [0.65, 2.14] | 0.21 | 0.59 | 0.16 [0.65, 2.05] | 0.21 | 0.62 | 0.98 [0.59, 1.63] | NEd | 0.94 |
Breast cancer | 2 | 452/396 | 0.80 [0.63, 1.01] | 0.33 | 0.06 | 0.75 [0.18, 3.15] | 0.00c | 0.69 | 0.83 [0.24, 2.83] | 0.00c | 0.76 | 1.20 [0.89, 1.61] | 0.37 | 0.24 |
Other cancers | 5 | 789/1,002 | 1.23 [0.83, 1.83] | 0.10 | 0.3 | 1.65 [0.92, 2.93] | 0.04c | 0.09 | 1.48 [0.82, 2.68] | 0.00c | 0.19 | 0.69 [0.42, 1.13] | 0.09c | 0.14 |
Sources of controls | ||||||||||||||
Hospital based | 11 | 2,929/3,139 | 0.81 [0.53, 1.22] | 0.03c | 0.31 | 0.89 [0.63, 1.26] | 0.03c | 0.52 | 0.85 [0.63, 1.17] | 0.06c | 0.32 | 0.85 [0.62, 1.15] | 0.05c | 0.29 |
Population based | 11 | 2,974/4,993 | 1.03 [0.89, 1.19] | 0.51 | 0.68 | 1.19 [0.91, 1.56] | 0.00c | 0.21 | 0.15 [0.91, 1.45] | 0.00c | 0.24 | 0.96 [0.80, 1.16] | 0.02c | 0.69 |
0.00 means value <0.01
aNumber of studies
b P value of Q test for heterogeneity test
cRandom effects model was used when P value for heterogeneity test <0.10; otherwise, fixed effects model was used
dNot estimable