Table 2 Global DNA methylation in peripheral blood of breast cancer cases and healthy controls
From: Blood-based DNA methylation as biomarker for breast cancer: a systematic review
Measurements | Author, year [ref] | Study design | Assay (value) | Case no./control no. | Case age/control age (y)a | Meth (case) | Meth (control) | p value | Main findings |
|---|---|---|---|---|---|---|---|---|---|
β value | van Veldhoven K, 2015 [18] | Nested case–control | 450 K (EPIC cohort) (mean + SD) | 162/162 | 54.4/54.2 | 53.00 ± 0.39 | 53.18 ± 0.35 | 1.82E−05 | Epigenome-wide hypomethylation of DNA in samples from EPIC cohort. |
|  |  |  | 450 K (NOWAC cohort) (mean + SD) | 168/168 | 55.4/55.4 | 54.02 ± 0.45 | 54.02 ± 0.41 | 0.79 | |
| Â | Â | Â | WBGS (BGS cohort) (mean) | 548/548 | 52/52 | 48.12 | 48.3 | na | |
|  | Severi G, 2014 [19] | Nested case–control | 450 K (mean + SD) | 420/420 | 64/64 | 51.86 ± 1.00 | 51.95 ± 1.01 | 0.006 | Epigenome-wide hypomethylation of DNA in BC patients. |
LUMA | Kuchiba A, 2014 [36] | Case–control | LUMA (% DNA meth) | 384/384 | 54.1/53.9 | 68.9 ± 3.5 | 70.2 ± 3.4 | <0.01 | Global genomic hypomethylation in BC patients. |
|  | Xu X, 2012 [29] | Case–control | LUMA (%) | 1055/1101 | na/na | 57.3 ± 15.7 | 52.4 ± 16.7 | <0.0001 | Global promoter hypermethylation in patients. |
|  | Delgado-Cruzata L, 2012 [32] | Case–control | LUMA (%) | 263/321 | 49.5/48.0 | 67.1 ± 7.6 | 67.5 ± 7.3 | >0.05 | LUMA DNA methylation levels were similar between cases and controls. |
5-mdC | Choi JY, 2009 [26] | Case–control | LC-MS (test set) (mean) | 19/18 | 35–75/35–75 | 3.98 | 4.33 | 0.001 | Hypomethylation of 5-mdC in BC patients. |
|  |  |  | LC-MS (validation set) (mean) | 176/173 | 35–75/35–75 | 4.18 ± 0.34 | 4.38 ± 0.36 | <0.001 | |
LINE-1 | Kitkumthorn N, 2012 [33] | Case–control | COBRA (%) | 36/144 | 50.28/48.67 | 40 | 42 | >0.05 | No significant differences in LINE-1 methylation between BC cases and healthy controls. |
|  | Xu X, 2012 [29] | Case–control | Pyrosequencing (mean) | 1064/1100 | na/na | 78.8 | 78.8 | 0.94 | As above. |
| Â | Brennan K, 2012 [17] | Â | Pyrosequencing (mean and IQR) | Â | Â | Â | Â | Â | As above. |
|  |  | Case–control | BGS cohort | 241/242 | 54/54 | 79.0 (78.1–79.9) | 79.0 (77.9–80.1) | 0.96 | |
|  |  | Case–control | EPIC cohort | 232/263 | 52/52 | 75.2 (73.9–76.3) | 75.1 (73.9–76.3) | 0.89 | |
|  |  | Nested case–control | KConFab cohort | 153/218 | 50/60 | 76.6 (75.2–77.6) | 76.0 (74.3–78.0) | 0.2 | |
|  | Wu HC, 2012 [31] | Case–control | MethyLight (%) | 265/333 | 49.5/48.0 | 107.4 ± 63.6 | 108.5 ± 59.1 | >0.05 | As above. |
|  |  |  | Pyrosequencing (mean) | 279/340 | 49.5/48.0 | 74.5 ± 3.0 | 74.5 ± 2.6 | >0.05 | |
|  | Cho YH, 2010 [27] | Case–control | MethyLight (%) | 40/40 | 50.8/48.3 | 70 | 78 | >0.05 | As above. |
|  | Choi JY, 2009 [26] | Case–control | Pyrosequencing (mean) | 19/18 | 35–75/35–75 | 74.7 | 73.9 | 0.176 | As above. |
|  | Deroo LA, 2014 [38]b | Nested case–control | Pyrosequencing | 294/646 | 57.9/na | na | na | na | As above. |
Sat2 | Wu HC, 2012 [31] | Case–control | MethyLight (%) | 266/333 | 49.5/48.0 | 41.3 ± 24.4 | 43.5 ± 32.9 | >0.05 | No significant differences in Sat2 methylation between BC cases and healthy controls. |
|  | Cho YH, 2010 [27] | Case–control | MethyLight (%) | 40/40 | 50.8/48.3 | 125 | 150 | 0.01 | Hypomethylation of Sat2 inpatients. |
Alu | Wu HC, 2012 [31] | Case–control | MethyLight (%) | 266/334 | 49.5/48.0 | 95.5 ± 36.6 | 98.7 ± 51.5 | >0.05 | No significant differences in Alu methylation between BC cases and healthy controls. |
|  | Cho YH, 2010 [27] | Case–control | MethyLight (%) | 40/40 | 50.8/48.3 | 58 | 61 | >0.05 | As above. |
[3H]-methyl | Delgado-Cruzata L, 2012 [32] | Case–control | [3H]-Methyl acceptance assay | 233/295 | 49.6/48.2 | 97,111 ± 76,348 | 88,030 ± 70,841 | <0.05 | Global genomic hypomethylation in BC patients (more [3H]-methyl acceptance). |