Table 1 Summary of the 11 most studied DNA methylation biomarkers for CRC in liquid biopsies

ALX4

3 [14,15,16]

Serum

46.6–88.0%

66.3–70.0%

2 [17, 18]

Plasma

28.5–80.0%

41.0–99.0%

APC

2 [19, 20]

Stool

-

-

1 [21]

Serum

6.1%

100%

2 [17, 22]

Plasma

20.8–42-0%

67.6–94.2%

CDKN2A

3 [19, 23, 24]

Stool

20.0–40.0%

96.8–100%

1 [25]

Serum

59.0–80.0

100%

2 [17, 26]

Plasma

9.3–61.1%

96.1%

1 [27]

Peripheral blood

55.4%

98.5%

MGMT

3 [19, 28, 29]

Stool

46.0–51.7%

93.8%

1 [30]

Serum

90.0%

100%

2 [17, 22]

Plasma

5.7%

99.0%

MLH1

3 [19, 20, 28]

Stool

30.0%

-

1 [21]

Serum

42.9%

97.6%

1 [17]

Plasma

45.1%

46.9%

NDRG4

6 [31,32,33,34,35,36]

Stool

28.6–76.2%

80.0–97.5%

2 [17, 37]

Plasma

9.3–27.0%

95.0–100%

1 [35]

Total blood

54.8%

78.1%

1 [35]

Urine

72.6%

85.0%

SDC2

2 [36, 38]

Stool

81.1%

93.3%

2 [31, 39]

Serum

71.2–87.0%

95.2–95.6%

1 [17]

Plasma

24.4%

94.1%

1 [40]

White blood cells

-

-

sFRP1

2 [16, 41]

Stool

52.0–89.0%

86.0–92.0%

1 [42]

Serum

77.7%

70.0%

2 [17, 43]

Plasma

21.8–62.9%

91.7–93.1%

sFRP2

9 [24, 29, 32, 34, 44,45,46,47,48]

Stool

57.1–94.2%

54.0–100%

2 [45, 48]

Serum

66.9–86.8%

93.7%

2 [17, 49]

Plasma

20.2–54.4%

72.3–82.4%

TFPI2

4 [34, 36, 50, 51]

Stool

31.4–89.0%

79.0–100%

1 [17]

Plasma

7.3%

98.0%

VIM

4 [28, 52,53,54]

Stool

38.3–81.0%

82.0–100%

2 [15, 55]

Serum

31.1–32.6%

60%

1 [17]

Plasma

17.6%

88.2%