Colorectal Neoplasms, Hereditary NonpolyposisLipomatosis, Multiple SymmetricalColorectal NeoplasmsAge of OnsetColonoscopyColonic NeoplasmsAdenomaRectal NeoplasmsEarly Detection of CancerSigmoidoscopyFluorouracilAdenocarcinomaColonic PolypsPrognosisNeoplasm MetastasisOrganoplatinum CompoundsNeoplasm StagingOccult BloodTumor Markers, BiologicalLeucovorinGene Expression Regulation, NeoplasticCamptothecinLiver NeoplasmsRisk FactorsMass ScreeningMutationColonGenetic Predisposition to DiseaseProspective StudiesHT29 CellsCarcinomaSurvival AnalysisCell Line, TumorHCT116 CellsSurvival RateAntineoplastic Combined Chemotherapy ProtocolsCarcinoembryonic AntigenRectumMicrosatellite InstabilityNeoplasm ProteinsMicrosatellite RepeatsColorectal SurgeryAdenomatous PolypsRetrospective StudiesDNA MethylationFollow-Up StudiesCase-Control StudiesNeoplasm InvasivenessAntineoplastic AgentsImmunohistochemistryMutS Homolog 2 ProteinAdenomatous Polyposis ColiDNA, NeoplasmDisease ProgressionAge FactorsTreatment OutcomeTime FactorsRisk