Background
Methods
Literature screening
Inclusion and exclusion criteria
Data extraction
Statistical analysis
Results
Literature search and screening results
Basic information of the included studies
First author
|
Year
|
Country
|
Ethnicity
|
Polymorphisms
|
Number of cases
|
Number of controls
|
Method
|
HWE
|
---|---|---|---|---|---|---|---|---|
Helmig | 2010 | Germany | European | TNF-α 308G/A | 374 | 177 | Real-time PCR | Yes |
Flego | 2009 | Croatia | European | TNF-α 308G/A | 230 | 230 | PCR-RFLP | Yes |
Stankovic | 2009 | Serbia | European | TNF-α 308G/A | 70 | 102 | PCR-RFLP | Yes |
Colakogullari | 2008 | Turkey | European | TNF-α 308G/A IL-6 174G/C | 44 | 59 | PCR-SSP | Yes |
Vogel | 2008 | Denmark | European | IL-6 174G/C | 403 | 744 | PCR | Yes |
Seifart | 2006 | Germany | European | TNF-α 308G/A IL-6 174G/C | 117 | 243 | PCR-RFLP | Yes |
Shih | 2006 | China | Asian | TNF-α 308G/A | 202 | 205 | PCR-RFLP | Yes |
Campa | 2004 | Norway | European | IL-6 174G/C | 250 | 214 | Taqman | Yes |
Locus
|
Research
|
Number of case
|
Number of control
|
Number of case
|
Number of control
| ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
GG
|
GA
|
AA
|
GG
|
GA
|
AA
|
G
|
A
|
G
|
A
| ||
TNF-α 308G/A | Helmig et al. | 290 | 79 | 5 | 136 | 38 | 3 | 659 | 89 | 310 | 44 |
Flego et al. | 169 | 52 | 9 | 171 | 53 | 6 | 390 | 70 | 395 | 65 | |
Stankovic et al. | 57 | 13 | 0 | 71 | 28 | 3 | 127 | 13 | 170 | 34 | |
Colakogullari et al. | 38 | 5 | 0 | 37 | 16 | 6 | 81 | 5 | 90 | 28 | |
Seifart et al. | 29 | 11 | 0 | 171 | 67 | 4 | 69 | 11 | 409 | 75 | |
Shih et al. | 110 | 75 | 15 | 169 | 34 | 2 | 295 | 105 | 372 | 38 | |
GG | GC | CC | GG | GC | CC | G | C | G | C | ||
IL-6 174G/C | Colakogullari et al. | 10 | 29 | 5 | 27 | 22 | 9 | 49 | 39 | 76 | 40 |
Vogel et al. | 105 | 202 | 96 | 204 | 361 | 179 | 412 | 394 | 769 | 719 | |
Seifart et al. | 19 | 16 | 4 | 90 | 107 | 46 | 54 | 24 | 287 | 199 | |
Campa et al. | 64 | 111 | 68 | 55 | 105 | 47 | 239 | 247 | 215 | 199 |
Combination of quantitative data
TNF-α-308G/A and lung cancer susceptibility
Locus
|
Comparison
|
OR (95% CI)
|
Z
|
P
A
|
I
2
|
P
Q
|
Model
|
Egger’s test
| |
---|---|---|---|---|---|---|---|---|---|
t
value
|
P
value
| ||||||||
TNF-α 308G/A | GG + GA vs. AA | 0.95 (0.30 to 2.99) | 0.08 | 0.935 | 55.6 | 0.046 | R | 1.38 | 0.240 |
GG vs. GA + AA | 1.07 (0.55 to 2.10) | 0.21 | 0.834 | 88.0 | 0.000 | R | 1.39 | 0.238 | |
GA vs. AA | 0.81 (0.43 to 1.54) | 0.64 | 0.524 | 0.0 | 0.503 | F | 1.85 | 0.138 | |
GG vs. AA | 1.00 (0.27 to 3.62) | 0.01 | 0.994 | 65.0 | 0.014 | R | 1.28 | 0.2708 | |
G vs. A | 1.12 (0.58 to 2.14) | 0.34 | 0.734 | 89.6 | 0.000 | R | 1.58 | 0.190 | |
IL-6 174G/C | GG + GC vs. CC | 1.10 (0.73 to 1.64) | 0.44 | 0.658 | 61.4 | 0.051 | R | 0.36 | 0.752 |
GG vs. GC + CC | 1.02 (0.81 to 1.27) | 0.15 | 0.879 | 17.4 | 0.304 | F | −0.98 | 0.432 | |
GC vs. CC | 1.13 (0.73 to 1.77) | 0.55 | 0.581 | 64.4 | 0.038 | R | 0.53 | 0.647 | |
GG vs. CC | 1.04 (0.80 to 1.36) | 0.29 | 0.771 | 9.4 | 0.346 | F | −0.46 | 0.693 | |
G vs. C | 1.03 (0.90 to 1.18) | 0.49 | 0.623 | 44.3 | 0.145 | F | −0.08 | 0.943 |
Coefficient
|
Standard Error
|
t
|
P
|
95% CI
| |
---|---|---|---|---|---|
Region | 2.652 | 1.235 | 2.15 | 0.121 | −1.278 to 6.582 |
Detection method | −0.741 | 0.933 | −0.79 | 0.485 | −3.710 to 2.229 |
Constant | −3.278 | 2.817 | −1.16 | 0.329 | −12.244 to 5.687 |
N
|
I
2
|
P
value for heterogeneity
|
OR (95% CI)
|
Z
|
P
| ||
---|---|---|---|---|---|---|---|
Region | Europe | 5 | 12.2 | 0.336 | 1.40 (0.70 to 2.78) | 0.95 | 0.342 |
Asia | 1 | 0.12 (0.03 to 0.54) | 2.77 | 0.006 | |||
Detection method | Real-time PCR | 1 | 1.27 (0.30 to 5.39) | 0.33 | 0.743 | ||
PCR-RFLP | 4 | 54.5 | 0.086 | 0.60 (0.15 to 2.38) | 0.73 | 0.465 | |
PCR-SSP | 1 | 10.57 (0.58 to 192.90) | 1.59 | 0.112 |