Hereditary Non-polyposis Colorectal Cancer (HNPCC), which affects nearly 5 percent of colorectal cancer patients, is characterized by a mutation in an important ...CORONAVIRUS:DELAYSFORROUTINESURGERIES,VISITORRESTRICTIONS+COVID-19TESTING.Home/HealthLibrary/Disease&ConditionsHereditaryNon-polyposisColorectalCancer(HNPCC)HereditaryNon-polyposisColorectalCancer(HNPCC)Appointments&AccessContactUsColorectalcanceristhethirdmostcommonformofcancerintheUnitedStates,withapproximately130,000casesdiagnosedeachyear.ItisalsothesecondleadingcauseofcancerdeathsintheUnitedStates.However,whendiscoveredearly,thediseaseis90percentcurable.Abnormalitiesinsomeofthegenesincoloncellsthatcontrolcellgrowthanddeathcancausecolorectalcancer.HereditaryNon-polyposisColorectalCancer(HNPCC),whichaffectsnearly5percentofcolorectalcancerpatients,ischaracterizedbyamutationinanimportantgene,whichisinherited--orpassedfromparenttochild.InHNPCC,the“H”standsforhereditary,meaningitisinheritedorcanbepassedfromparenttochild.“NP”standsfornon-polyposis,whichdistinguishesHNPCCfromasyndromecharacterizedbytheformationofpolyps.The“CC”standsforcolorectalcancer,themostfrequentcancerthatdevelopsinHNPCCfamilies.HowisHNPCCinherited?HNPCCiscausedbyaninheritedmutationorabnormalityinagenethatnormallyrepairsourbody'sDNA.ThereareatleastfiveofthesegenesknownasmismatchrepairgenesthatareknowntobeassociatedwithHNPCC.Ifgeneticdamageisnotrepaired,cancercanoccur.Whenanindividualhasaninheritedgenemutation,itispresentinthecellsofallorgansofthebody.Thismakesiteasierforothercancerstodevelop,suchascanceroftheuterusorovaries,gastrointestinaltract(stomach,smallintestineandpancreas),urinarytractorkidneys.HNPCCandcancerriskbyage70ColorectalCancerLifetimeriskofcancerinHNPCC: 80%Riskingeneralpopulation: 2%Endometrial(uterine)CancerLifetimeriskofcancerinHNPCC: 60%Riskingeneralpopulation: 1.5%OvarianCancer LifetimeriskofcancerinHNPCC:12%Riskingeneralpopulation:1%StomachCancerLifetimeriskofcancerinHNPCC:13%Riskingeneralpopulation: Lessthan1%Otherc