From: Association of COMT Val158Met polymorphism and breast cancer risk: an updated meta-analysis
Comparison | Population | Sample size | No. of studies | Test of association | Mode | Test of heterogeneity | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
 |  | Case | Control |  | OR | 95% CI | P value |  | χ 2 | P value | I 2 |
LL vs. HH | Overall | 17,223 | 23,069 | 54 | 0.999 | 0.925-1.078 | 0.976 | R | 117.76 | 0.000 | 55.0 |
 | Caucasian | 12,942 | 18,066 | 32 | 0.960 | 0.897-1.028 | 0.240 | R | 49.28 | 0.020 | 37.1 |
 | Asian | 3,009 | 3,790 | 17 | 1.243 | 0.942-1.641 | 0.125 | R | 54.34 | 0.000 | 70.6 |
 | Pre- | 2,095 | 2,523 | 21 | 1.049 | 0.825-1.334 | 0.697 | R | 48.22 | 0.000 | 58.5 |
 | Post- | 7,215 | 10,138 | 26 | 0.982 | 0.875-1.102 | 0.757 | R | 45.40 | 0.008 | 44.9 |
 | PB | 17,223 | 23,069 | 28 | 0.999 | 0.925-1.078 | 0.381 | R | 48.00 | 0.008 | 43.7 |
 | HB | 3,800 | 6,169 | 20 | 1.151 | 0.946-1.402 | 0.160 | R | 58.86 | 0.000 | 67.7 |
 | FB | 1,351 | 1,140 | 5 | 0.848 | 0.712-1.010 | 0.064 | F | 4.43 | 0.351 | 9.7 |
HL vs. HH | Overall | 22,589 | 33,568 | 54 | 1.005 | 0.959-1.052 | 0.845 | R | 72.70 | 0.038 | 27.1 |
 | Caucasian | 19,059 | 25,912 | 32 | 0.999 | 0.958-1.042 | 0.968 | F | 30.14 | 0.510 | 0.0 |
 | Asian | 4,525 | 5,781 | 17 | 1.052 | 0.923-1.200 | 0.448 | R | 36.85 | 0.002 | 56.6 |
 | Pre- | 3,204 | 3,877 | 21 | 0.962 | 0.871-1.062 | 0.440 | F | 27.59 | 0.119 | 27.5 |
 | Post- | 10,480 | 14,476 | 26 | 1.009 | 0.954-1.067 | 0.762 | F | 33.83 | 0.112 | 26.1 |
 | PB | 17,648 | 22,679 | 28 | 0.987 | 0.945-1.030 | 0.547 | F | 3.60 | 0.463 | 0.0 |
 | HB | 5,751 | 9,128 | 20 | 1.075 | 0.966-1.195 | 0.187 | R | 33.89 | 0.019 | 43.9 |
 | FB | 2,102 | 1,674 | 5 | 0.950 | 0.824-1.094 | 0.476 | F | 30.98 | 0.272 | 12.9 |
LL vs. HL | Overall | 23,594 | 31,759 | 54 | 0.983 | 0.926-1.045 | 0.586 | R | 95.26 | 0.000 | 44.4 |
 | Caucasian | 19,579 | 27,208 | 32 | 0.954 | 0.911-1.001 | 0.055 | F | 36.02 | 0.245 | 13.9 |
 | Asian | 2,538 | 3,135 | 17 | 1.170 | 0.895-1.528 | 0.251 | R | 49.83 | 0.000 | 67.9 |
 | Pre- | 2,507 | 3,200 | 21 | 1.060 | 0.851-1.320 | 0.606 | R | 49.32 | 0.000 | 59.4 |
 | Post- | 10,243 | 14,548 | 26 | 0.969 | 0.915-1.025 | 0.271 | F | 32.47 | 0.271 | 23.0 |
 | PB | 16,437 | 21,768 | 28 | 0.969 | 0.909-1.032 | 0.324 | R | 39.76 | 0.054 | 32.1 |
 | HB | 4,973 | 8,203 | 20 | 1.060 | 0.902-1.245 | 0.478 | R | 48.71 | 0.000 | 61.0 |
 | FB | 2,099 | 1,714 | 5 | 0.882 | 0.769-1.012 | 0.073 | F | 4.37 | 0.358 | 8.6 |
LL vs. HL+HH | Overall | 34,358 | 45,429 | 56 | 0.988 | 0.929-1.050 | 0.702 | R | 108.88 | 0.000 | 51.3 |
 | Caucasian | 25,790 | 35,593 | 32 | 0.956 | 0.909-1.006 | 0.081 | R | 43.54 | 0.067 | 28.8 |
 | Asian | 5,770 | 7,552 | 17 | 1.204 | 0.927-1.564 | 0.164 | R | 52.91 | 0.000 | 69.8 |
 | Pre- | 3,903 | 4.800 | 21 | 1.053 | 0.855-1.297 | 0.627 | R | 49.44 | 0.000 | 59.5 |
 | Post- | 13,969 | 19,581 | 26 | 0.980 | 0.901-1.065 | 0.629 | R | 37.85 | 0.048 | 33.9 |
 | PB | 24,205 | 31,307 | 30 | 0.966 | 0.906-1.030 | 0.290 | R | 45.36 | 0.015 | 40.5 |
 | HB | 7,262 | 11,750 | 20 | 1.098 | 0.934-1.289 | 0.257 | R | 54.38 | 0.000 | 65.1 |
 | FB | 2,776 | 2,264 | 5 | 0.877 | 0.760-1.013 | 0.074 | F | 4.62 | 0.328 | 13.5 |
LL+HL vs. HH | Overall | 34,358 | 45,429 | 56 | 1.001 | 0.954-1.051 | 0.953 | R | 93.20 | 0.001 | 41.0 |
 | Caucasian | 25,790 | 35,593 | 32 | 0.982 | 0.944-1.022 | 0.369 | F | 37.71 | 0.189 | 17.8 |
 | Asian | 5,770 | 7,552 | 17 | 1.072 | 0.952-1.208 | 0.253 | R | 42.65 | 0.001 | 60.1 |
 | Pre- | 3,933 | 4.839 | 22 | 1.016 | 0.890-1.160 | 0.815 | R | 33.81 | 0.038 | 37.9 |
 | Post- | 14,001 | 19,604 | 27 | 1.001 | 0.924-1.084 | 0.987 | R | 40.17 | 0.038 | 35.3 |
 | PB | 24,205 | 31,307 | 30 | 0.975 | 0.924-1.028 | 0.343 | R | 42.89 | 0.047 | 32.4 |
 | HB | 7,262 | 11,750 | 20 | 1.091 | 0.978-1.216 | 0.118 | R | 39.26 | 0.004 | 51.6 |
 | FB | 2,776 | 2,264 | 5 | 0.914 | 0.799-1.044 | 0.186 | F | 3.81 | 0.432 | 0.0 |