In15-40%ofprimarybreastcancers,amplificationoftheHER-2oncogenisfoundwhichishighlycorrelatedwithoverexpressionoftheencoded185kDaproteinandseemstoplayamajorroleespeciallyduringtheinitiationofductalcarcinomas.HER-2proteinoverexpressionisdescribedasindependentprognosticfactorwithgreaterpredictivepowerthanmostofthecurrentlyusedprognostictools-especiallyinaxillarylymph-node-positivebreastcancerpatients.StudiesanalyzingsmallseriesofpatientshavesuggestedaprognosticvalueforHER-2oncoproteinexpressioninaxillarynodenegative(ANN)patients.AnassociationbetweenoncoproteinexpressionanddecreasedoverallsurvivalamongANNpatientswithgoodnucleargradetumorshasbeendemonstrated.Inadditionithasbeenreportedthatinlowriskpatients(estrogenreceptorpositive,smalltumors),HER-2proteinexpressionwasassociatedwithearlyrecurrence.DatademonstratethelargebodyofevidenceimplicatingHER-2oncoproteinintheBIOLOGyandprognosisofbreastcarcinoma.32%ofovariancarcinomasoverexpresstheHER-2oncoprotein.SurvivalofthosepatientsissignificantlyworsecomparedwithcasesofnormalHER-2proteinexpression.Additionally,patientswhosetumorshavehighp185proteinexpressionaresignificantlylesslikelytohaveacompleteresponsetoprimarytherapy.Alsonon-smallcelllungcancerswhichexpresstheHER-2proteindosoathigherlevelsthanthosefoundinnormalbronchialepithelium,andexpressioninadenocarcinomaofthelungisindependentlyassociatedwithdiminishedsurvival.AcorrelationbetweenHER-2proteinexpression,andclinicaloutcomehasbeenalsodemonstratedforheadandneck,salivaryglandandplacentalcarcinomas.HER-2proteinisusefulinidentifyingcancercellswithincreasedaggressiveness.Solublep97-115HER-2(thesolublecirculatingfragmentofp185HER-2)proteinlevelsinserumcanbeusedasdiagnostictoolformonitoringtheextentoftumorspread,postoperativerelapseand/ormetastaticriskfordifferentcancers.

Synonyms:p185ERBB2,C-erbB2,NEU-protooncogene