大肠结肠癌colorectal cancer

ColorectalCancerWhatisit?•ItisthethirdmostfrequentlydiagnosedcancerinmenandwomenandthesecondhighestcauseofcancerdeathsintheU.S.•Yet,whenfoundearly,itishighlycurable.Thistypeofcanceroccurswhenabnormalcellsgrowintheliningofthelargeintestine(colon)orrectum.Learnmoreaboutwhogetscolorectalcancer,howitisdetected,andwhatthelatesttreatmentscanaccomplish.Howitstarts?•Itoftenbeginaspolyps–benigngrowthsonthesurfaceofthecolon.•Thetwomostcommontypesofintestinalpolypsareadenomasandhyperplasicpolyps.Theydevelopwhenthereareerrorsinthewaycellsgrowandrepairtheliningofthecolon.Mostpolypsremainbenign,butsomehavethepotentialtoturncancerous.Removingthemearlypreventscolorectalcancer.RiskFactorsYouCan'tControlgenetics&lifestyle.•Age–mostpatientsareolderthan50•Polypsorinflammatoryboweldisease•Familyhistoryofcolorectalcancer•HistoryofovarianorbreastcancerRiskFactorsYouCanControl•Diethighinred,processed,orheavilycookedmeats•Beingoverweight(excessfataroundthewaist)•Exercisingtoolittle•SmokingordrinkingalcoholItswarningSigns•Thereareusuallynoearlywarningsignsforcolorectalcancer.Forthisreasonit'simportanttogetscreened.•Detectingcancerearlymeansit'smorecurable.Asthediseaseprogresses,patientsmaynoticebloodinthestool,abdominalpain,achangeinbowelhabits(suchasconstipationordiarrhea),unexplainedweightloss,orfatigue.Bythetimethesesymptomsappear,tumorstendtobelargerandmoredifficulttotreat.Screening•Becausecolorectalcancerisstealthy,screeningsarethekeytoearlydetection.Beginningatage50,mostpeopleshouldhaveacolonoscopyevery10years.Thisprocedureusesatinycameratoexaminetheentirecolonandrectum.Thesetestsnotonlyfindtumorsearly,butcanactuallypreventcolorectalcancerbyremovingpolyps(shownhere).VirtualColonoscopy•ThereisnowanalternativetocolonoscopythatusesCTscanimagestoconstructa3-Dmodelofyourcolon.Calledvirtualcolonoscopy,theprocedurecanrevealpolypsorotherabnormalitieswithoutactuallyinsertingacamerainsideyourbody.Themaindisadvantageisthatifpolypsarefound,arealcolonoscopywillstillbeneededtoremoveandevaluatethem.X-RaysoftheColon(LowerGI)•X-Raysofthecolon--usingachalkyliquidknownasbariumasacontrastagent--allowyourdoctoraglimpseattheinteriorofthecolonandrectum,offeringanotherwaytodetectpolyps,tumors,andchangesintheintestinaltissue.Shownhereisanapplecoretumorconstrictingthecolon.Likethevirtualcolonoscopy,anyabnormalitiesthatappearontheX-rayswillneedtobefollowedupwithaconventionalcolonoscopy.DiagnosingColorectalCancer•Iftestingrevealsapossibletumor,thenextstepisabiopsy.Duringacolonoscopy,yourdoctorwillremovepolypsandtaketissuesamplesfromanypartsofthecolonthatlookunusual.Thistissueisexaminedunderamicroscopetodeterminewhetherornotitiscancerous.Shownhereisacolor-enhanced,magnifiedviewofcoloncancercells.StagingColorectalCancer•Ifcancerisdetected,itwillbestaged,aprocessoffindingouthowfarthecancerhasspread.Tumorsizemaynotcorrelatewiththestageofcancer.Stagingalsoenablesyourdoctortodeterminewhattypeoftreatmentyouwillreceive.•I–Cancerhasnotspreadbeyondtheinsideofthecolonorrectum•II–Cancerhasspreadintothemusclelayerofthecolonorrectum•III-Cancerhasspreadtooneormorelymphnodesinthearea•IV–Cancerhasspreadtootherpartsofthebody,suchastheliver,lung,orbones.ThisstagedoesNOTdependonhowdeepthetumorhaspenetratedorifthediseasehasspreadtothelymphnodesnearthetumor.ColorectalCancerSurvivalRates•Theoutlookforyourrecoverydependsonthestageofyourcancer,withhigherstagesmeaningmoreseriouscancer.Thefive-yearsurvivalratereferstothepercentageofpatientswholiveatleastfiveyearsafterbeingdiagnosed.StageIhasa93%five-yearsurvivalratewhilestageIVhasafive-yearsurvivalrateofonly8%.ColorectalCancerSurgery•Inallbutthelaststageofcolorectalcancer,theusualtreatmentissurgerytoremovethetumorandsurroundingtissue.Inthecaseoflargertumors,itmaybenecessarytotakeoutanentiresectionofthecolonand/orrectum.Thegoodnewsisthatsurgeryhasaveryhighcurerateintheearlystages.Ifthecancerhasspreadtotheliver,lungs,orotherorgans,surgeryisnotlikelytoofferacure--butremovingtheadditionaltumors,whenpossible,mayreducesymptoms.TreatingAdvancedColorectalCancer•Whencolorectalcancerhasspreadtooneormorelymphnodes(stageIII),itcanstillbecured.Treatmenttypicallyinvolvesacombinationofsurgery,radiation(beingadministeredhere),andchemotherapy.Ifthecancercomesbackafterinitialtreatmentorspreadstootherorgans,itbecomesmuchmoredifficulttocure.Butradiationandchemotherapycanstillrelievesymptomsandhelppatientslivelonger.CopingWithChemotherapy•Chemotherapyhascomealongwayfromthedaysofturningpeople'sstomachs.Newerdrugsarelesslikelytocausethisproblem,andtherearealsomedicationstocontrolnauseaifitdoesoccur.Clinicaltrialscontinuetosearchforchemotherapydrugsthataremoreeffectiveandtolerable.RadiofrequencyAblation•Radiofrequencyablation(RFA)usesintenseheattoburnawaytumors.GuidedbyaCTscan,adoctorinsertsaneedle-likedevicethatdeliversheatdirectlytoatumorandthesurroundingarea.Thisoffersanalternativefordestroyingtumorsthatcannotbesurgicallyremoved.Inpatientswithalimitednumberoflivermetastasesthatcannotberemovedbysurgery,chemotherapyissometimescombinedwithRFAfortumordest