P values of likelihood ratio tests (LR; clinical vs. clinical plus methylation data), apparent error (AE), 10-fold cross-validated prediction error (PE), and explained variation R2 (PE based R2 value), computed for 18-months follow-up.

For LR, the clinical prognostic factors were used as a reference (Ref.). For R2, Kaplan-Meier was used as a reference (Ref.). MSP, methylation-specific polymerase chain reaction; dPSQ (CpG 1–5), dichotomised pyrosequencing data for CpG 1–5; dMS-MLPA, dichotomised methylation-specific multiplex ligation-dependent probe amplification data for site 1–3. N/A, not applicable.