The-AJCC-Cancer-Staging-Manual-and-Handbook-c2

ColonandRectum1431414ColonandRectum(Sarcomas,lymphomas,andcarcinoidtumorsofthelargeintestinearenotincluded)At-A-GlanceSUMMARYOFCHANGES●Inthesixthedition,StageIIwassubdividedintoIIAandIIBonthebasisofwhethertheprimarytumorwasT3N0orT4N0,respectively,andStageIIIwassubdividedintoIIIA(T1-2N1M0),IIIB(T3-4N1M0),orIIIC(anyTN2M0).Intheseventhedition,furthersubstagingofStageIIandIIIhasbeenaccomplished,basedonsurvivalandrelapsedatathatwasnotavailablefortheprioredition●ExpandeddatasetshaveshowndifferentialprognosiswithinT4lesionsbasedonextentofdisease.AccordinglyT4lesionsaresubdividedasT4a(Tumorpenetratesthesurfaceofthevisceralperitoneum)andasT4b.(Tumordirectlyinvadesorishistologicallyadherenttootherorgansorstructures)●Thepotentialimportanceofsatellitetumordepositsisnowdefinedbythenewsite-specificfactorTumorDeposits(TD)thatdescribetheirtextureandnumber.T1-2lesionsthatlackregionallymphnodemetastasisbuthavetumordeposit(s)willbeclassifiedinadditionasN1c●ThenumberofnodesinvolvedwithmetastasisinfluencesprognosiswithinbothN1andN2groups.AccordinglyN1willbesubdividedasN1a(metastasisin1regionalnode)andN1b(metastasisin2–3nodes),andN2willbesubdividedasN2a(metastasisin4–6nodes)andN2b(metastasisin7ormorenodes)●StageGroupIIissubdividedintoIIA(T3N0),IIB(T4aN0)andIIC(T4bN0)●StageGroupIII:●AcategoryofN1lesions,T4bN1,thatwasformerlyclassifiedasIIIBwasfoundtohaveoutcomesmoreakintoIIICandhasbeenreclassifiedfromIIIBtoIIIC●Similarly,severalcategoriesofN2lesionsformerlyclassifiedasIIIChaveoutcomesmoreakintootherstagegroups;therefore,T1N2ahasbeenreclassifiedasIIIAandT1N2b,T2N2a-b,andT3N2ahaveallbeenreclassifiedasIIIB●M1hasbeensubdividedintoM1aforsinglemetastaticsitevs.M1bformultiplemeta-staticsites144AmericanJointCommitteeonCancer�2010INTRODUCTIONTheTNMclassificationforcarcinomasofthecolonandrec-tumprovidesmoredetailthanotherstagingsystems.Compat-iblewiththeDukes’system,theTNMaddsgreaterprecisionintheidentificationofprognosticsubgroups.TNMstagingisbasedonthedepthoftumorinvasionintoorbeyondthewallofthecolorectum(T),invasionoforadherencetoadjacentorgansorstructures(T),thenumberofregionallymphnodesinvolved(N),andthepresenceorabsenceofdistantmetasta-sis(M).TheTNMclassificationappliestobothclinicalandpathologicstaging.Mostcancersofthecolonandmanycan-cersoftherectumarestagedafterpathologicexaminationofaresectedspecimen.However,patientswithhigh-riskrectalcancersarecommonlyreceivingpreoperativeadjuvanttreat-mentpriortosurgicalresectionandpathologicalstageanno-tationshouldemploytheyprefixinsuchcases.Thisstagingsystemappliestoallcarcinomasarisinginthecolonorrec-tum.Adenocarcinomasofthevermiformappendixareclas-sifiedaccordingtotheTNMstagingsystemforappendix(seeChap.13),whereascancersthatoccurintheanalcanalarestagedaccordingtotheclassificationusedfortheanus(seeChap.15).Well-differentiatedneuroendocrinecarcinomas(carcinoidtumors)ofthecolorectumareclassifiedaccord-ingtotheTNMstagingsystemforgastric,smallbowel,andcolonicandrectalcarcinoidtumors(well-differentiatedneu-roendocrinetumorsandwell-differentiatedneuroendocrinecarcinomas)asdescribedinChap.17.ANATOMYThedivisionsofthecolonandrectumareasfollows:CecumAscendingcolonHepaticflexureTransversecolonSplenicflexureDescendingcolonANATOMICSTAGE/PROGNOSTICGROUPSStageTNMDukes*MAC*0TisN0M0––IT1N0M0AAT2N0M0AB1IIAT3N0M0BB2IIBT4aN0M0BB2IICT4bN0M0BB3IIIAT1–T2N1/N1cM0CC1T1N2aM0CC1IIIBT3–T4aN1/N1cM0CC2T2–T3N2aM0CC1/C2T1–T2N2bM0CC1IIICT4aN2aM0CC2T3–T4aN2bM0CC2T4bN1–N2M0CC3IVAAnyTAnyNM1a––IVBAnyTAnyNM1b––ICD-O-3TOPOGRAPHYCODESC18.0CecumC18.2AscendingcolonC18.3HepaticflexureofcolonC18.4TransversecolonC18.5SplenicflexureofcolonC18.6DescendingcolonC18.7SigmoidcolonC18.8OverlappinglesionofcolonC18.9Colon,NOSC19.9RectosigmoidjunctionC20.9Rectum,NOSICD-O-3HISTOLOGYCODERANGES8000–8152,8154–8231,8243–8245,8250–8576,8940–8950,8980–8981Note:cTNMistheclinicalclassification,pTNMisthepathologicclassification.Theyprefixisusedforthosecancersthatareclassifiedafterneoadjuvantpretreatment(e.g.,ypTNM).PatientswhohaveacompletepathologicresponseareypT0N0cM0thatmaybesimilartoStageGroup0orI.Therprefixistobeusedforthosecancersthathaverecurredafteradisease-freeinterval(rTNM).*DukesBisacompositeofbetter(T3N0M0)andworse(T4N0M0)prognosticgroups,asisDukesC(AnyTN1M0andAnyTN2M0).MACisthemodifiedAstler-Collerclassification.ColonandRectum14514SigmoidcolonRectosigmoidjunctionRectumPrimarySite.Thelargeintestine(colorectum)extendsfromtheterminalileumtotheanalcanal.Excludingtherec-tumandvermiformappendix,thecolonisdividedintofourparts:therightorascendingcolon,themiddleortransversecolon,theleftordescendingcolon,andthesigmoidcolon.Thesigmoidcoloniscontinuouswiththerectumwhichter-minatesattheanalcanal.Thececumisalarge,blindpouchthatarisesfromtheproximalsegmentoftherightcolon.Itmeasures6–9cminlengthandiscoveredwithavisceralperitoneum(serosa).Theascendingcolonmeasures15–20cminlength.Theposteriorsurfaceoftheascending(anddescending)colonlacksperito-neumandthusisindirectcontactwiththeretroperitoneum.Incontrast,theanteriorandlateralsurfacesoftheascending(anddescending)colonhaveserosaandareintrap