Objective:Ki-67playsanimportantfunctionincellpision,butitsexactroleisstillunknown.Moreover,fewworksregardingitsoverallfunctionwerepublished.ThepresentstudyevaluatedtheclinicalsignificanceofKi-67indexasaprognosticmarkerandpredictorofrecurrenceindifferentmolecularsubtypesofbreastcancer.TherelationshipofKi-67indexwithdifferentclinicopathologicalfactorswasalsoanalyzed.Methods:Ki-67indexwasmeasuredin107casesofprimarybreastcancerfrom2010-2012.Thesepatientswereevaluatedforestrogenreceptor,progesteronereceptor,andHER2.Ki-67waspidedaccordingtopercentagelevels:<15%and>15%.Followuprangedfrom32monthsupto6years.Results:Approximately44,23,15,and25casesweregroupedasluminalA,luminalB,HER2subtype,andtriple-negative(TN),respectively.NoluminalApatientsshowedKi-67levelhigherthan15%,andtheirrecurrencewas20%.InluminalBgroup,Ki-67levelhigherthan15%wasobservedin69%ofpatients,andrecurrencewas39%.InHER2subtype,Ki-67washigherthan15%in34%ofcases,andrecurrencewas40%.Intriple-negativecases,Ki-67washigherthan15%in60%ofcases,andrecurrencewasdetectedin32%ofpatients.PatientswithKi-67lessthan15%displayedbetteroverallsurvivalthanthosewithKi-67higherthan15%(P=0.01).PatientswithKi-67higherthan15%exhibitedhigherincidenceofmetastasisandrecurrencethanthosewithKi-67lessthan15%(P=0.000).Conclusions:Ki-67maybeconsideredasavaluablebiomarkerinbreastcancerpatients.
