Mammograms - National Cancer Institute

Screening mammograms usually involve two or more x-ray pictures, or images, of each breast. The x-ray images often make it possible to detect ... Skiptomaincontent Español 1-800-4-CANCER LiveChat Publications Dictionary Home CancerTypes BreastCancer BreastCancer Patient BreastCancerTreatment MaleBreastCancerTreatment ChildhoodBreastCancerTreatment BreastCancerDuringPregnancy BreastCancerPrevention BreastCancerScreening HealthProfessional BreastCancerTreatment MaleBreastCancerTreatment ChildhoodBreastCancerTreatment BreastCancerTreatmentDuringPregnancy BreastCancerPrevention GeneticsofBreast&GynecologicCancers BreastCancerScreening ResearchAdvances ResearchArticles Mammograms OnThisPage Whatisamammogram? Howarescreeninganddiagnosticmammogramsdifferent? Whatarethebenefitsandpotentialharmsofscreeningmammograms? WherecanIfindcurrentrecommendationsforscreeningmammography? Whatisthebestmethodof screeningfor breastcancer? WhatistheBreastImagingReportingandDatabaseSystem(BI-RADS®)? Wherecanwomengethigh-qualitymammograms? Howmuchdoesamammogramcost? Howcanuninsuredorlow-incomewomenobtainafreeorlow-costscreeningmammogram? Whatshouldwomenwithbreastimplantsdoaboutscreeningmammograms? Whatisdigitalmammography?Howisitdifferentfromconventional(film)mammography? Whatis3-Dmammography(alsoknownastomosynthesismammography)? Whatothertechnologiesorstrategiesarebeingdevelopedforbreastcancerscreening? Whatisamammogram? Amammogramisanx-raypictureofthebreast. Mammogramscanbeusedtocheckforbreastcancerinwomenwhohavenosignsorsymptomsofthedisease.Thistypeofmammogramiscalledascreeningmammogram.Screeningmammogramsusuallyinvolvetwoormorex-raypictures,orimages,ofeachbreast.Thex-rayimagesoftenmakeitpossibletodetecttumorsthatcannotbefelt.Screeningmammogramscanalsofindmicrocalcifications(tinydepositsofcalcium)thatsometimesindicatethepresenceofbreastcancer. Mammogramscanalsobeusedtocheckforbreastcancerafteralumporothersignorsymptomofthediseasehasbeenfound.Thistypeofmammogramiscalledadiagnosticmammogram.Besidesalump,signsofbreastcancercanincludebreastpain,thickeningoftheskinofthebreast,nippledischarge,orachangeinbreastsizeorshape;however,thesesignsmayalsobesignsofbenignconditions.Adiagnosticmammogramcanalsobeusedtoevaluatechangesfoundduringascreeningmammogramortoviewbreasttissuewhenitisdifficulttoobtainascreeningmammogrambecauseofspecialcircumstances,suchasthepresenceofbreastimplants. Howarescreeninganddiagnosticmammogramsdifferent? Thesamemachinesareusedforbothtypesofmammograms.However,diagnosticmammographytakeslongertoperformthanscreeningmammographyandthetotaldoseofradiationishigherbecausemorex-rayimagesareneededtoobtainviewsofthebreastfromseveralangles.Thetechnologistmaymagnifyasuspiciousareatoproduceadetailedpicturethatcanhelpthedoctormakeanaccuratediagnosis. Whatarethebenefitsandpotentialharmsofscreeningmammograms? Earlydetectionofbreastcancerwithscreeningmammographymeansthattreatmentcanbestartedearlierinthecourseofthedisease,possiblybeforeithasspread.Randomizedclinicaltrialsandotherstudiesshowthatscreeningmammographycanhelpreducedeathsfrombreastcanceramongwomenages40to74yearsataverageriskofbreastcancer,withtheevidenceofbenefitbeingstrongestforwomenages50to69years (1,2).However,nostudiestodatehaveshownabenefitfromregularscreeningmammographyinwomenunderage40orfrombaselinescreeningmammograms(mammogramsusedforcomparison)takenbeforeage40. Thebenefitsofscreeningmammographyneedtobebalancedagainst itsharms,whichinclude: False-positiveresults.False-positiveresultsoccurwhenradiologistsseeanabnormality(thatis,apotential“positive”)onamammogram butnocancerisactuallypresent.Allabnormalmammogramsshouldbefollowedupwithadditionaltesting(diagnosticmammograms,ultrasound,and/orbiopsy)todeterminewhethercancerispresent. False-positivemammogramresultscanleadtoanxietyandotherformsofpsychologicaldistressinaffectedwomen.Theadditionaltestingrequiredtoruleoutcancercanalsobecostlyandtimeconsumingandcancausephysicaldiscomfort. False-positiveresultsaremorecommonforyoungerwomen,womenwithdensebreasts,womenwhohavehadpreviousbreastbiopsies,womenwithafamilyhistoryofbreastcancer,andwomenwhoaretakingestrogen(forexample,menopausalhormonetherapy).Thechanceofhavingafalse-positiveresultincreaseswiththenumberofmammogramsawomanhas.Morethan50%ofwomenscreenedannuallyfor10yearsintheUnitedStateswillexperienceafalse-positiveresult,andmanyofthesewomenwillhaveabiopsy. Overdiagnosisandovertreatment.Screeningmammogramscanfindcancersandcasesofductalcarcinomainsitu(DCIS,anoninvasivetumorinwhichabnormalcellsthatmaybecomecancerousbuildupintheliningofbreastducts)thatneedtobetreated.However,theycanalsofindcasesofDCISandsmallcancersthatwouldnevercausesymptomsorthreatenawoman’slife.Thisphenomenoniscalled "overdiagnosis."TreatmentofoverdiagnosedcancersandoverdiagnosedcasesofDCISisnotneededandresultsin"overtreatment." Becausedoctors cannoteasilydistinguishcancersandcasesofDCISthatneedtobetreatedfromthosethatdonot,theyarealltreated. False-negativeresults.Incancerscreening,anegativeresultmeansnoabnormalityispresent.False-negativeresultsoccurwhenmammogramsappearnormaleventhoughbreastcancerispresent.Overall,screeningmammogramsmissabout20%ofbreastcancersthatarepresentatthetimeofscreening.False-negativeresultscanleadtodelaysintreatmentandafalsesenseofsecurityforaffectedwomen. Onecauseoffalse-negativeresultsishighbreastdensity.Breastscontainbothdensetissue(i.e.,glandulartissueandconnectivetissue,togetherknownasfibroglandulartissue)andfattytissue.Fattytissueappearsdarkonamammogram,whereasfibroglandulartissueappearsaswhiteareas.Becausefibroglandulartissueandtumorshavesimilardensity,tumorscanbehardertodetectinwomenwithdenserbreasts. False-negativeresultsoccurmoreoftenamongyoungerwomenthanamongolderwomenbecauseyoungerwomenaremorelikelytohavedensebreasts.Asawomanages,herbreastsusuallybecomemorefatty,andfalse-negativeresultsbecomelesslikely. Somebreastcancersgrowsoquicklythattheyappearwithinmonthsofanormal(negative)screeningmammogram.Thissituationdoesnotrepresentafalse-negativeresult,becausethenegativeresultofthescreeningwascorrect.Butitmeansthatanegativeresultcangiveafalsesenseofsecurity.Someofthecancersmissedbyscreeningmammogramscanbedetectedbyclinicalbreastexams(physicalexamsofthebreastdonebyahealthcareprovider). Findingbreastcancerearly maynotreduceawoman’schanceofdyingfromthedisease.Eventhoughmammogramscandetectmalignanttumorsthatcannotbefelt,treatingasmalltumordoesnotalwaysmeanthatthewomanwillnotdiefromthecancer.Afast-growingoraggressivecancermayhavealreadyspreadtootherpartsofthebodybeforeitisdetected.Instead,womenwithsuchtumorslivealongerperiodoftimeknowingthattheylikelyhaveapotentiallyfataldisease. Inaddition,findingbreastcancerearlymaynothelpprolongthelifeofawomanwhoissufferingfromother,morelife-threateninghealthconditions. Radiationexposure.Mammogramsrequireverysmalldosesofradiation.Theriskofharmfromthisradiationexposureislow,butrepeatedx-rayshavethepotentialtocausecancer.Althoughthepotentialbenefitsofmammographynearlyalwaysoutweighthepotentialharmfromtheradiationexposure,womenshouldtalkwiththeirhealthcareprovidersabouttheneedforeachx-ray.Inaddition,theyshouldalwayslettheirhealthcareproviderandthex-raytechnologistknowifthereisanypossibilitythattheyarepregnant,becauseradiationcanharmagrowingfetus. WherecanIfindcurrentrecommendationsforscreeningmammography? Manyorganizationsandprofessionalsocieties,includingtheUnitedStatesPreventiveServicesTaskForce(whichisconvenedbytheAgencyforHealthcareResearchandQuality,afederalagency),havedevelopedguidelinesformammographyscreening,assummarizedbytheCentersforDiseaseControlandPrevention(CDC).Allrecommendthatwomentalkwiththeirdoctoraboutthebenefitsandharmsofmammography,whentostartscreening,andhowoftentobescreened. AlthoughNCIdoesnotissueguidelinesforcancerscreening,it conductsandfacilitatesbasic,clinical, andtranslationalresearchthatinformsstandardclinicalpracticeandmedicaldecisionmaking thatotherorganizationsmayuse todevelop guidelines. Whatisthebestmethodof screeningfor breastcancer? Regular high-qualityscreeningmammogramsand clinicalbreastexamsarethemost sensitivewaysto screenfor breastcancer. Regularbreastself-exam,orBSE—thatis,checkingone’sownbreastsforlumpsorotherunusualchanges—isnotspecificallyrecommendedforbreastcancerscreening. Inclinicaltrials,BSEalonewasnotfoundtohelpreducethenumberofdeathsfrombreastcancer. However,manywomenchoosetoexaminetheirownbreasts.Womenwhodososhouldrememberthatbreastchangescanoccurbecauseofpregnancy,aging,ormenopause;duringmenstrualcycles;orwhentakingbirthcontrolpillsorotherhormones.Itisnormalforbreaststofeelalittlelumpyanduneven.Also,itiscommonforbreaststobeswollenandtenderrightbeforeorduringamenstrualperiod.Wheneverawomannoticesanyunusualchangesinherbreasts,sheshouldcontactherhealthcareprovider. WhatistheBreastImagingReportingandDatabaseSystem(BI-RADS®)? TheAmericanCollegeofRadiology(ACR)hasestablishedauniformwayforradiologiststodescribemammogramfindings.Thesystem,calledBI-RADS,includessevenstandardizedcategories,orlevels.EachBI-RADScategoryhasafollow-upplanassociatedwithittohelpradiologistsandotherphysiciansappropriatelymanageapatient’scare. BreastImagingReportingandDatabaseSystem(BI-RADS) Category Assessment Follow-up 0 Needadditionalimagingevaluation Additionalimagingneededbeforeacategorycanbeassigned 1 Negative Continueregularscreeningmammograms 2 Benign(noncancerous)finding Continueregularscreeningmammograms 3 Probablybenign Receivea6-monthfollow-upmammogram 4 Suspiciousabnormality Mayrequirebiopsy 5 Highlysuggestiveofmalignancy(cancer) Requiresbiopsy 6 Knownbiopsy-provenmalignancy(cancer) Biopsyconfirmspresenceofcancerbeforetreatmentbegins BI-RADSalsoincludesfourcategoriesofbreastdensitythatmaybereported.Theradiologistwhoreadsthemammogramchoosesthecategorythatbestdescribesthelevelofbreastdensityseenonthemammogramfilm.Thecategories,fromtheleastamountofbreastdensitytothehighest,areasfollows: Thebreastsarealmostentirelyfatty Therearescatteredareasofdenseglandulartissueandfibrousconnectivetissue(togetherknownasfibroglandulardensity) Thebreastsareheterogeneouslydense,whichmeanstheyhavemoreoftheseareasoffibroglandulardensity.Thismaymakeithardtoseesmallmassesinthebreasttissueonamammogram. Thebreastsareextremelydense,whichmakesithardtoseetumorsinthebreasttissueonamammogram. ManystatesintheU.S.haveenactedlawsrequiringmammographyproviderstotellwomeniftheyhavedensebreasts(i.e.,breaststhatareheterogeneouslyorextremelydenseonamammogram)andtoinformthemofrisksassociatedwithhavingdensebreasts.Inadditiontomakingmammogramshardertoread,densebreastsareariskfactorforbreastcancer. Wherecanwomengethigh-qualitymammograms? Womencangethigh-qualitymammogramsinbreastclinics,hospitalradiologydepartments,mobilevans,privateradiologyoffices,anddoctors’offices. TheMammographyQualityStandardsAct(MQSA)isafederallawthatrequiresmammographyfacilitiesacrossthenationtomeetuniformqualitystandards.Underthelaw,allmammographyfacilitiesmust:1)beaccreditedbyanFDA-approvedaccreditationbody;2)becertifiedbytheFDA,oranagencyofastatethathasbeenapprovedbytheFDA,asmeetingthestandards;3)undergoanannualMQSAinspection;and4)prominentlydisplaythecertificateissuedbytheagency.MoreinformationaboutMQSAisavailablefromtheFDA. WomencanasktheirdoctorsorstaffatalocalmammographyfacilityaboutFDAcertificationbeforemakinganappointment.WomenshouldlookfortheMQSAcertificateatthemammographyfacilityandcheckitsexpirationdate.MQSAregulationsalsorequirethatmammographyfacilitiesgivepatientsaneasy-to-readreportoftheirmammogramresults. InformationaboutlocalFDA-certifiedmammographyfacilitiesisavailablethroughNCI’sCancerInformationServiceat1–800–4–CANCER(1–800–422–6237).Also,asearchablelistofthesefacilitiescanbefoundontheFDAwebsite. Howmuchdoesamammogramcost? InsuranceplansgovernedbythefederalAffordableCareActmustcoverscreeningmammographyasapreventivebenefitevery1–2yearsforwomenage40andoverwithoutrequiringcopayments,coinsurance,ordeductibles.Inaddition,manystatesrequirethatMedicaidandpublicemployeehealthplanscoverscreeningmammography.Women shouldcontacttheirmammographyfacilityorhealthinsurancecompanyforconfirmationofthecostandcoverage. MedicarepaysforannualscreeningmammogramsforallfemaleMedicarebeneficiarieswhoareage40orolder.Medicarewillalsopayforonebaselinemammogramforfemalebeneficiariesbetweentheagesof35and39.Thereisnodeductiblerequirementforthisbenefit.InformationaboutcoverageofmammogramsisavailableontheMedicarewebsiteorthroughtheMedicareHotlineat1–800–MEDICARE(1–800–633–4227).Forthehearingimpaired,thetelephonenumberis1–877–486–2048. Womenwhoneedadiagnosticmammogramshouldcheckwiththeirhealthinsuranceprovideraboutcoverage. Howcanuninsuredorlow-incomewomenobtainafreeorlow-costscreeningmammogram? Somestateandlocalhealthprogramsandemployersprovidemammogramsfreeoratlowcost.Forexample,theCentersforDiseaseControlandPrevention(CDC)coordinatestheNationalBreastandCervicalCancerEarlyDetectionProgram.Thisprogramprovidesscreeningservices,includingclinicalbreastexamsandmammograms,tolow-income,uninsuredwomenthroughouttheUnitedStatesandinseveralU.S.territories.ContactinformationforlocalprogramsisavailableontheCDCwebsiteorbycalling1–800–CDC–INFO(1–800–232–4636). Informationaboutfreeorlow-costmammographyscreeningprogramsisalsoavailablefromNCI’sCancerInformationServiceat1–800–4–CANCER(1–800–422–6237)andfromlocalhospitals,healthdepartments,women’scenters,orothercommunitygroups. Whatshouldwomenwithbreastimplantsdoaboutscreeningmammograms? Womenwithbreastimplantsshouldcontinuetohavemammograms.(Awomanwhohadanimplantfollowingamastectomyshouldaskherdoctorwhetheramammogramofthereconstructedbreastisnecessary.) Implantscanhidesomebreasttissue,makingitmoredifficultfortheradiologisttodetectanabnormalityonthemammogram.Itisimportanttoletthemammographyfacilityknowaboutbreastimplantswhenschedulingamammogram.Thetechnologistandradiologistmustbeexperiencedinperformingmammographyonwomenwhohavebreastimplants.  Ifthetechnologistperformingtheprocedureisawarethatawomanhasbreastimplants,stepscanbetakentomakesurethatasmuchbreasttissueaspossiblecanbeseenonthemammogram.Aspecialtechniquecalledimplantdisplacementviewsmaybeused. Whatisdigitalmammography?Howisitdifferentfromconventional(film)mammography? IntheUnitedStates,digitalmammographyhasreplacedconventionalmammography.Digitalandconventionalmammographybothusex-raystoproduceanimageofthebreast;however,inconventionalmammography,theimageisstoreddirectlyonfilm,whereas,indigitalmammography,anelectronicimageofthebreastisstoredasacomputerfile.Thisdigitalinformationcanbeenhanced,magnified,ormanipulatedforfurtherevaluationmoreeasilythaninformationstoredonfilm.Digitalimagescanalsobesharedelectronically,makingvirtual(remote)consultationsbetweenradiologistsandbreastsurgeonseasier. DigitalmammographycanbedoneonlyinfacilitiesthatarecertifiedtopracticeconventionalmammographyandhavereceivedFDAapprovaltoofferdigitalmammography.Theprocedureforhavingamammogramwithadigitalsystemisthesameaswithconventionalmammography. Whatis3-Dmammography(alsoknownastomosynthesismammography)? Three-dimensional(3-D)mammography,alsoknownasdigitalbreasttomosynthesis(DBT),isatypeofdigitalmammographyinwhichx-raymachinesareusedtotakepicturesofthin"slices"ofthebreastfromdifferentanglesandcomputersoftwareisusedtoreconstructanimage.Thisprocessissimilartohowacomputedtomography(CT)scannerproducesimagesofstructuresinsideofthebody.3-Dmammographyusesverylowdosex-rays,but,becauseitisgenerallyperformedatthesametimeasstandardtwo-dimensional(2-D)digitalmammography,theradiationdoseishigherthanthatofstandardmammography.NewertomosynthesisstrategiesallowDBTtobedonealone,potentiallyreducingtheradiationdosetoalevelclosertothatofstandardmammography. AlthoughmanywomenareofferedDBT,ithasnotyetbeendeterminedconclusivelywhetheritissuperiorto2-Dmammographyatidentifyingearlycancersandavoidingfalse-positiveresults. Alarge-scalerandomizedbreastscreeningtrialiscomparing3-Dmammographywith2-Dmammography.TheTomosynthesisMammographyImagingScreeningTrial(TMIST) iscomparingthenumberofadvancedcancersdetectedinwomenscreenedfor4yearswithDBTwiththatdetectedinwomenscreenedwithstandarddigitalmammography.  Whatothertechnologiesorstrategiesarebeingdevelopedforbreastcancerscreening? NCIissupportingthedevelopmentofseveralnewtechnologiestodetectbreasttumors.Thisresearchrangesfrommethodsbeingdevelopedinresearchlabstothosethatarebeingstudiedinclinicaltrials.Effortstoimproveconventionalmammographyincludedigitalmammography,magneticresonanceimaging(MRI),positronemissiontomography(PET)scanning,anddiffuseopticaltomography,whichuseslightinsteadofx-raystocreatepicturesofthebreast. TheWomenInformedtoScreenDependingonMeasuresofRisk(WISDOM)studyisarandomizedtrialthatistestingapersonalizedapproachtobreastcancerscreening.This5-yearstudy,whichwillinvolveabout100,000womeninCaliforniaandtheMidwest,aimstodetermineifrisk-basedscreening—thatis,screeningatintervalsthatarebasedoneachwoman’sriskasdeterminedbyhergeneticmakeup,familyhistory,andotherriskfactors—isassafe,effective,andacceptedasannualscreening.