Kaplan Meier analysis revealed that the worst overall survival was significantly associated with ERCC1 and MGMT methylation...The methylation of MGMT, alone or combined with ERCC1, is predictive for poor prognosis, short overall survival and chemotherapy response in colorectal cancer....Importantly, ERCC1 methylation was negatively associated with FOLFOX chemoresistance (p = 0.002)....Multivariate Cox proportional hazards model analysis confirmed that MGMT methylation was an independent predictive biomarker of short OS (p ≤ 0.001)...Our study showed an association between the simultaneous methylation of these genes and FOLFOX response.