Meta-Analysis
Copyright ©2014 Baishideng Publishing Group Inc.
World J Gastroenterol. Aug 28, 2014; 20(32): 11429-11438
Published online Aug 28, 2014. doi: 10.3748/wjg.v20.i32.11429
Table 1 Characteristics of eligible studies included in the meta-analysis
Ref.CountryEthnicitySample size
C677T
A1298C
Genotypes distribution
Alleles frequency
PGenotypes distribution
Alleles frequency
P
CaseControlCase
Control
Case
Control
HWECase
Control
Case
Control
HWE
CCCTTTCCCTTTCTCTAAACCCAAACCCACAC
Gao et al[12]ChinaEastern26453511510544277207513351937613090.19
Guo et al[13]ChinaEastern97114224827325725921021211070.97
Saberi et al[14]IranEastern405780198172354223085057824211524080.54
Yang et al[15]ChinaEastern1391654480156275281681101971310.5
Cui et al[16]South KoreaEastern22131700778105238254086329726081816194314570.13
De Re et al[17]ItalyWestern48961223133746134749120720.7324195335496729120720.08
Galvan-Portillo et al[18]MexicoWestern2484783713279892171722162903955610.17
Gotze et al[19]GermanyWestern10610646451241491613769131810.74
Zeybek et al[20]TurkeyEastern35144181256465154822193950.76
Vollset et al[21]Europea1Western24763110910432248277943221687734650.2710311625315246533221668763520.61
Mu et al[22]ChinaEastern1963975010638135199572061824693130.231474902751127343496621260.25
Zhang et al[23]PolandWestern30542714611633185178364081825482500.4813512531180179413951875392610.72
Boccia et al[24]ItalyWestern1022542951229811541109953111970.435043912510722143613571510.89
Fu et al[25]ChinaEastern1691699673012544026573294440.12
Graziano et al[26]ItalyWestern1621643486426768291541262021260.10
Li et al[27]ChinaEastern170140617831675617200140190900.321264229741229446235450.32
Weng et al[28]ChinaEastern38341419515118472941270.062612022111641255130.79
Kim et al[29]South KoreaEastern133445426427143239631481185253650.022983413081298230367451450.19
Si et al[30]ChinaEastern1221015848164943916480141610.92734455838519054154480.70
Sarbia et al[31]GermanyWestern33225513815341107115334292353291810.81
Bi et al[32]ChinaEastern309188139150209776154281902701060.99
Wang et al[33]ChinaEastern1293152545597414398951632913390.12
Stolzenberg-Solomon et al[34]ChinaEastern9039817363765209124701103394570.14692102941040159216921040.0032
Miao et al[35]ChinaEastern21746847107631512171002012335194170.181506433241395364707871490.022
Gao et al[36]ChinaEastern1072002261246399381051092251750.93
Shen et al[37]ChinaEastern1871665590426080262001742001320.9613055211150531559272600.83
Table 2 Distribution of MTHFR C677T and A1298C genotypes and alleles frequency in gastric cardia cancer, non-cardia cancer and controls
Ref.Sample size
Genotypes distribution
Alleles frequency
CardiaNon-cardiaControlCardiaNon-cardiaControlCardiaNon-cardiaControl
MTHFR C677T polymorphismCCCTTTCCCTTTCCCTTTCTCTCT
Saberi et al[14]15221078077601599981342230850214902961241152408
Gotze et al[19]2776106131313332114149163915985413181
Graziano et al[26]43119164725112761316768293947115123202126
Weng et al[28]NA3834NA1419515118NA47294127
Sarbia et al[31]1192132556545973108321071153317563254172329181
Si et al[30]29931012171374115494394991157114161
Bi et al[32]1551541887473865771297761521189207101270106
Wang et al[33]129NA315254559NA741439895163NA291339
Stolzenberg-Solomon et al[34]90NA398173637NA6520912470110NA339457
Miao et al[35]217NA4684710763NA151217100201233NA519417
Shen et al[37]82105166223822335220608026828211892200132
MTHFR A1298C polymorphismAAACCCAAACCCAAACCCACACAC
Weng et al[28]NA3834NA2612022111NA64125513
Si et al[30]299310115122583235838542161483815448
Shen et al[37]821051666417166381111505145191704027260
Table 3 Distribution of MTHFR C677T and A1298C genotypes and alleles frequency in intestinal, diffuse gastric cancer and controls
Ref.Sample size
Genotypes distribution
Alleles frequency
IntestinalDiffuseControlIntestinal
Diffuse
Control
Intestinal
Diffuse
Control
CCCTTTCCCTTTCCCTTTCTCTCT
MTHFR C677T polymorphism
Saberi et al[14]14280780695914393474223085019787112481152408
Galvan-Portillo et al[18]88152454503811339291163NANANA
Gotze et al[19]533710621248181544149166640512313181
Graziano et al[26]917116419472515391767682985976973202126
Table 4 Comparisons of MTHFR C677T and A1298C polymorphisms for whole and stratified analysis
nCase/controlOR (95%CI)PPHeterogeneityOR (95%CI)PPHeterogeneityOR (95%CI)PPHeterogeneityOR (95%CI)PPHeterogeneity
(TT + CT)/CCT/CTT/CCTT/(CT + CC)
C677T
Total246266/82501.23 (1.08, 1.40)0.002< 0.00011.15 (1.06, 1.25)0.0010.00041.37 (1.15, 1.63)0.00050.00051.17 (1.07, 1.28)0.00080.01
Eastern164716/58391.26 (1.08, 1.47)0.0030.0021.21 (1.08, 1.34)0.00050.0021.42 (1.15, 1.76)0.0010.0051.22 (1.09, 1.35)0.00030.03
Western81550/24111.20 (0.92, 1.56)0.1800.0021.05 (0.91, 1.21)0.530.051.28 (0.91, 1.82)0.160.0091.05 (0.88, 1.25)0.550.11
Tumor site
Cardia
Total101043/29411.09 (0.81, 1.48)0.5600.00051.16 (0.95, 1.41)0.140.0021.28 (0.85, 1.95)0.240.0031.38 (1.15, 1.67)0.00060.05
Eastern7854/24161.16 (0.89, 1.52)0.2800.051.24 (1.04, 1.48)0.020.061.57(1.23, 2.00)0.00030.161.53 (1.25, 1.87)< 0.00010.31
Western3189/5251.09 (0.38, 3.12)0.8700.0011.00 (0.52, 1.91)1.000.0040.78 (0.15, 4.16)0.770.0030.73 (0.27, 1.99)0.540.07
Non-cardia
Total81008/17941.38 (1.18, 1.63)< 0.00010.421.24 (1.10, 1.40)0.00030.421.44 (1.09, 1.91)0.010.311.19 (0.93, 1.52)0.160.61
Eastern5600/12691.35 (1.10, 1.66)0.0040.991.21 (1.04, 1.41)0.010.871.30 (0.87, 1.95)0.200.481.10 (0.79, 1.55)0.570.44
Western3408/5251.41 (0.83, 2.38)0.4000.031.26 (0.91, 1.76)0.160.061.55 (0.86, 2.78)0.140.121.29 (0.91, 1.83)0.160.53
Lauren’s classification
Intestinal
Total4374/15041.46 (0.86, 2.47)0.1600.051.33 (0.97, 1.84)0.080.101.88 (1.22, 2.89)0.0040.191.45 (1.07, 1.95)0.020.76
Eastern1142/7801.25 (0.87,1.87)0.230NA1.25 (0.95, 1.64)0.12NA1.71 (0.90, 3.26)0.10NA1.60 (0.86, 2.97)0.14NA
Western3232/7241.61 (0.60,4.29)0.3400.031.37 (0.74, 2.52)0.320.042.01 (1.13, 3.59)0.020.071.41 (1.00, 1.98)0.050.58
Diffuse
Total4340/15041.31 (0.66,2.58)0.4400.031.19 (0.78, 1.82)0.420.061.46 (0.66, 3.21)0.350.130.94 (0.56, 1.58)0.820.09
Eastern180/7801.24 (0.78,1.96)0.360NA1.21 (0.85, 1.73)0.29NA1.51 (0.64, 3.57)0.34NA1.40 (0.61, 3.20)0.80NA
Western3260/7241.33 (0.35,5.01)0.6700.0081.14 (0.50, 2.60)0.760.021.31 (0.29, 5.83)0.720.040.85 (0.46, 1.55)0.590.1
A1298C(CC + AC)/AAC/ACC/AACC/(AC + AA)
Total112007/36790.98 (0.79, 1.21)0.8400.0080.97 (0.83, 1.14)0.730.030.95 (0.71, 1.28)0.760.600.95 (0.72, 1.27)0.750.78
Eastern71015/14520.96 (0.72, 1.29)0.7900.020.93 (0.73, 1.19)0.560.040.44 (0.21, 0.93)0.030.840.46 (0.22, 0.96)0.040
Western4702/14081.00 (0.71, 1.41)0.9900.041.07 (0.93, 1.23)0.360.151.13 (0.82, 1.57)0.460.691.11 (0.81, 1.51)0.530.98
Tumor site
Cardia
Total2111/2670.80 (0.37, 1.74)0.2400.130.83 (0.41, 1.69)0.610.100.76 (0.21, 2.83)0.690.280.80 (0.22, 2.93)0.730.36
Eastern2111/2670.80 (0.37, 1.74)0.2400.130.83 (0.41, 1.69)0.610.100.76 (0.21, 2.83)0.690.280.80 (0.22, 2.93)0.730.36
Western00NANANANA
Non-cardia
Total3236/3010.98 (0.69, 1.41)0.9300.590.93 (0.68, 1.26)0.620.690.45 (0.15, 1.40)0.170.860.46 (0.15, 1.40)0.170.82
Eastern3236/3010.98 (0.69, 1.41)0.9300.590.93 (0.68, 1.26)0.620.690.45 (0.15, 1.40)0.170.860.46 (0.15, 1.40)0.170.82
Western00NANANANA
Table 5 Comparisons of MTHFR C677T and A1298C polymorphisms for gastric cardia and non-cardia cancers, intestinal-type and diffuse-type gastric cancers
nCase/controlOR (95%CI)PPHeterogeneityOR (95%CI)PPHeterogeneityOR (95%CI)PPHeterogeneityOR (95%CI)PPHeterogeneity
C677T(TT + CT)/CCT/CTT/CCTT/(CT + CC)
Cardia and non-cardia
Total7607/9700.74 (0.51, 1.08)0.120.010.80 (0.59, 1.09)0.20.0020.82 (0.49, 1.38)0.460.010.71 (0.36, 1.39)0.310.06
Eastern4418/5620.76 (0.47, 1.21)0.240.040.85 (0.56, 1.27)0.40.011.04 (0.52, 2.06)0.910.050.89 (0.39, 2.03)0.780.10
Western3189/4080.75 (0.35, 1.61)0.460.040.73 (0.45, 1.20)0.20.050.59 (0.35, 1.00)0.050.080.52 (0.17, 1.59)0.250.26
Intestinal-type and diffuse-type
Total4374/3401.09 (0.74, 1.62)0.670.761.10 (0.84, 1.45)0.50.781.60 (1.09, 2.35)0.020.871.24 (0.68, 2.27)0.480.50
Eastern1142/801.01 (0.58, 1.74)0.98NA1.03 (0.68, 1.57)0.9NA1.14 (0.44, 2.95)0.79NA1.13 (0.42, 3.04)0.81NA
Western3232/2601.19 (0.68, 2.09)0.550.541.16 (0.81, 1.66)0.40.571.71 (1.13, 2.59)0.010.641.32 (0.62, 2.80)0.480.41
A1298C(CC + AC)/AAC/ACC/AACC/(AC + AA)
Cardia and non-cardia
Total2111/1980.83 (0.26, 2.64)0.750.030.90 (0.34, 2.34)0.80.031.87 (0.39, 9.03)0.440.591.85 (0.39, 8.69)0.430.75
Eastern2111/1990.83 (0.26, 2.64)0.750.030.90 (0.34, 2.34)0.80.031.87 (0.39, 9.03)0.440.591.85 (0.39, 8.69)0.430.75
Western00NANANANA