Table 2. Meta-regression and subgroup analysis of the studies reporting the association of LINE-1 hypomethylation and overall survival of cancer patients.
Stratified study | No. of studies | No. of patients | Fixed-Model (HR, 95%CI) | Random-Model (HR, 95%CI) | Meta-regression p value (%) | HG I2 (%) | HG p-value |
Year | 0.362 | ||||||
<2011 | 7 | 1342 | 1.40(1.10,1.77) | 1.46(0.83,2.58) | 77.5 | 0.001 | |
> = 2011 | 12 | 2247 | 1.88(1.57,2.24) | 2.09(1.51,2.91) | 56.9 | 0.006 | |
Hypomethylation cut-off | 0.603 | ||||||
Dichotomy | 16 | 2886 | 1.65(1.37,1.98) | 1.76(1.22,2.52) | 67.5 | 0.001 | |
Quartile | 3 | 703 | 1.76(1.40,2.20) | 2.15(1.25,3.71) | 73.3 | 0.001 | |
Hypomethylation rate | 0.067 | ||||||
< = 50% | 7 | 1010 | 1.92(1.57,2.35) | 2.52(1.72,3.71) | 54.2 | 0.033 | |
>50% | 12 | 2579 | 1.48(1.21,1.82) | 1.40(0.92,2.14) | 71.8 | 0.001 | |
Study race | 0.300 | ||||||
Yellow | 12 | 1729 | 1.76(1.47,2.11) | 2.08(1.50,2.89) | 55.8 | 0.035 | |
White | 7 | 1860 | 1.59(1.26,2.00) | 1.57(0.97,2.53) | 72.4 | 0.001 | |
Age | 0.423 | ||||||
< = 60 | 9 | 123 | 1.52(1.27,1.82) | 0.33(0.10,0.76) | 73.7 | 0.001 | |
>60 | 9 | 3438 | 1.86(1.45,2.72) | 1.93(1.44,2.58) | 15.9 | 0.308 | |
Method | 0.759 | ||||||
Pyrosequencing | 12 | 2365 | 1.90(1.57,2.30) | 0.54(0.15,0.93) | 60.8 | 0.003 | |
Others | 7 | 1224 | 1.45.(1.17.,1.80) | 1.70(0.96,3.02) | 73.2 | 0.001 | |
Bio-samples | 0.304 | ||||||
Tissue | 16 | 2617 | 1.61(1.38,1.87) | 1.55(1.11,0.93) | 69.3 | 0.001 | |
Blood | 3 | 972 | 2.84(1.76,4.59) | 2.84(1.76,4.59) | 0.00 | 0.948 | |
REMARK Score | 0.728 | ||||||
<17 | 10 | 1191 | 1.73(1.24,2.42) | 1.66(1.16,1.88) | 66.6 | 0.01 | |
> = 17 | 9 | 2398 | 1.68(1.44,1.97) | 1.89(1.36,2.62) | 69.1 | 0.001 | |
No. of patients | 0.536 | ||||||
>200 | 9 | 1031 | 1.68(1.31,2.17) | 1.65(1.00,2.70) | 66.1 | 0.001 | |
<200 | 10 | 2558 | 1.69(1.43,2.01) | 1.99(1.38,2.87) | 71.3 | 0.001 | |
Types of cancers | 0.972 | ||||||
digestive system, | 8 | 2873 | 1.89(1.50,2.39) | 2.07(1.24,3.44) | 74 | 0.001 | |
respiratory system tumors | 3 | 789 | 1.40(1.04,1.88) | 1.35(0.82,2.23) | 64.1 | 0.061 | |
other tumors | 8 | 1384 | 1.70(1.36,2.13) | 1.95(1.13,3.39) | 63.1 | 0.008 |
Abbreviations: CI = confidence interval; HR = hazard ration; HG: heterogeneity.