Table 2. Prognostic value of DNA methylation in plasma or serum.

Gene(s)	Name	Anatomical site	Stage	Local recurrence-free survival (hazard ratio)	Overall survival (hazard ratio)	Method	Reference
EDNRB/DCC/CDKN2A		All	All	1.35c (0.17–10.5)	1.35c (0.41–4.43)	qMSP	Mydlarz et al. [35]
SEPT91	Septin 9	All	All	-	5.27a (2.03–13.68)	qPCR	Schröck et al. [37]
SHOX21	Short statue Homeobox 2	All	All	-	2.32a (1.12–4.83)	qPCR	Schröck et al. [37]
SEPT91	Septin 9	All	All	1.32b (1.09–1.59)	1.23b (1.07–1.41)	qPCR	Schröck et al. [37]
SEPT92	Septin 9	All	All	-	2.78a(1.16–6.67)	qPCR	Schröck et al. [37]
SHOX22	Short statue Homeobox 2	All	All	-	2.50a (1.12–5.60)	qPCR	Schröck et al. [37]
SEPT91	Septin 9	All	All	-	1.90d (1.43–2.69)	quasi-digital PCR	De Vos et al. [38]
SHOX21	Short statue Homeobox 2	All	All	-	1.85d (1.18–2.91)	quasi-digital PCR	De Vos et al. [38]
SEPT92	Septin 9	All	All	-	1.67d (1.13–2.45)	quasi-digital PCR	De Vos et al. [38]
SHOX22	Short statue Homeobox 2	All	All	-	1.71d (1.05–2.80)	quasi-digital PCR	De Vos et al. [38]

a: Univariate cox proportional hazards analysis of the 129 cases with positive serum samples using the introduced cut-off value.

b: Multivariate cox proportional hazards analysis of the 129 cases using the DNA methylations levels as a continuous variable.

c: Univariate proportional hazards analysis.

d: Univariate cox proportional hazards analysis.

1: Training Cohort.

2: Testing Cohort.