Chemotherapy-induced ovarian toxicity in patients affected by endocrine-responsive early breast cancer.

(1)

Chemotherapy-induced

ovarian

toxicity

in

patients

affected

by

endocrine-responsive

early

breast

cancer

Francesco

Torino

a

,

Agnese

Barnabei

b

,

Liana

De

Vecchis

a

,

Valentina

Sini

c

,

Francesco

Schittulli

d

,

Paolo

Marchetti

e

,

Salvatore

Maria

Corsello

f,∗

a_Department_of_Systems_Medicine,_Chair_of_Medical_Oncology,_Tor_Vergata_University_of_Rome,_Italy b_{Endocrinology}_Unit,_Regina_Elena_National_Cancer_Institute,_Rome,_Italy

c_Surgical_and_Medical_Department_of_Clinical_Sciences,_Biomedical_Technologies_and_{Translational}_Medicine,_{“Sapienza”} UniversityofRome,Italy

d_Department_of_Women’s_Health,_Cancer_Institute_of_Bari,_Italy

e_Department_of_Clinical_and_Molecular_Medicine,_Medical_Oncology_Division,_{Sant’Andrea}_Hospital,_{“Sapienza”} UniversityofRomeandIDI-IRCCS,Rome,Italy

f_{Endocrinology}_Unit,_Università_Cattolica,_Rome,_Italy Accepted18July2013

Contents

1. Introduction ... 28

2. Ovarianinsufficiencyinducedbycytotoxicagents... 28

2.1. Definitions... 28

2.2. PathogenesisofPOFinducedbyCT... 31

2.3. ClinicalaspectsofPOF... 31

2.4. FactorspredictingtheonsetofPOFandresumptionofmensesinEBCpatients... 31

2.4.1. Age... 33

2.4.2. Cytotoxicregimens... 33

2.4.3. Endocrinetreatment... 34

2.4.4. Geneticfactors... 34

3. TheprognosticsignificanceofCRA,CRMandRMinpatientswithEBC... 34

4. Preservingfertilityinbreastcancerpatients... 34

5. Measuringovarianreserveinhealthywomenandinthosewithcancer... 35

6. Whenarepatientswithchemotherapy-relatedamenorrheaactuallymenopausal?... 36

7. OvarianreservemarkersandthechoiceofendocrinetherapyinEBCpatients ... 37

8. Conclusions ... 38 Conflictofinterest ... 38 Funding... 38 Reviewers... 38 References ... 38 Biographies... 42 Abstract

Cytotoxicchemotherapymayvariablyaffectovarianfunctiondependingonageandovarianreserveatdiagnosis,typeofchemotherapy anduseoftamoxifen.

Ascertainingwhetherapremenopausalpatientwithendocrine-responsiveearlybreastcancerandchemotherapy-inducedamenorrheahas reachedmenopauseisessentialnotonlyinordertoprovideaccurateinformationonresidualfertility,butalsotoappropriatelyprescribe

∗_{Corresponding}_author_at:_Largo_A._Gemelli,_8,_I-00168_Rome,_Italy._Tel.:₊₃₉₀₆_3219418;_fax:₊₃₉₀₆_32500063. E-mailaddress:[email protected](S.M.Corsello).

(2)

28 F.Torinoetal./CriticalReviewsinOncology/Hematology89(2014)27–42

endocrinetherapy.Indeed,aromataseinhibitorsare contraindicatedin womenwithresidualovarianreserve. However,the diagnosisof menopausein patientswith chemotherapy-inducedamenorrhea is challenging,sinceclinicalfeatures, follicle-stimulatinghormone and estradiollevelsmaybeinaccuratetothisaim.Recentstudiesdemonstratedthattheanti-müllerianhormonemayimprovetheassessmentof ovarianreserveresidualtochemotherapyinwomenwithearlybreastcancer.

Herein,wereviewtheincidenceofamenorrheaandmenopauseinducedbycytotoxicchemotherapyinwomenaffectedbyearlybreastcancer andthesuggestedmechanismsthatsustaintheseside-effects.Furthermore,ithasbeenscrutinizedthepotentialofnewmarkersofovarian reservethatmayfacilitatetheselectionofappropriateendocrinetreatmentforpremenopausalwomenwhodevelopamenorrheafollowing adjuvantchemotherapyforearlybreastcancer.

Keywords:Breastcancer;Chemotherapy-inducedamenorrhea;Chemotherapy-inducedmenopause;Aromataseinhibitors;Ovarianreserve

1. Introduction

Breastcancer (BC)is thesecond most common cancer inWesternCountriesandthemostcommoninvasive malig-nancy in reproductive-aged women [1,2]. Approximately 30%ofpatientsarepremenopausaland10%areaged35–44 atdiagnosis [3].Despitethefact thatBC inwomen under theageof 40isinfrequent(5.5%intheUnitedStates)[4], adramaticincreaseinthenumberofBCdiagnosedin pre-menopausal womenhasbeen reportedinseveralcountries

[5].BC,eveninearlystages(EBC),presentsmoreaggressive features,andprognosisispoorerinyoungercomparedwith olderwomen[6–8].Therefore,mostofthesepatientsreceive adjuvant cytotoxic treatments (CT) followedby endocrine therapy(ET)inthecaseofendocrine-responsive(ER+) dis-ease[9,10].

CTprolongssurvival ofpatientsaffectedbyEBC,even inthecaseofendocrine-responsive disease,particularlyin women under 50 [11]. However, in a variable percentage ofpre-/perimenopausalpatientsCTmaycauseamenorrhea (chemotherapy-related amenorrhea, CRA) or menopause (chemotherapy-related menopause, CRM). These side-effectsarepredictiveofimprovedclinicaloutcomesinmost clinical trials [12,13], but expose women to a number of physicalandsocio-psychologicaldistressesregarding resid-ualfertility,sexualdysfunction,boneloss andmenopausal symptoms,withamarkedlynegativeeffectonqualityoflife

[14].

Anumberof factorsinfluence theonsetof CRA/CRM, including age, type of CT received and use of tamoxifen (Table1).EstimationoftheindividualrisktodevelopCRA orCRM,however,remainsapproximate.

Nowadays,toascertainwhetherapatientwith endocrine-responsiveEBCandCRAisactuallymenopausalisofutmost importancenotonlyinordertoprovideaccurateinformation onresidual fertility,butalsofor prescribingthe most suit-ableET(i.e.,tamoxifenoraromataseinhibitors,AI).Indeed, onlyinpostmenopausalpatientsareAIrecommendedas up-fronttreatment, orsequentially aftertamoxifen, sincethey reduce the risk of recurrence [16]. Instead, AI as single agents are contraindicated in premenopausal patients and inthosepresentingresidual ovarianfunction[16].In these patients,theinappropriateuseofAIinducesatemporary inhi-bitionofestrogenproduction,leadingtoafeedbackincrease

in gonadotropinlevels, which, inturn, stimulatefollicular growth,aromataseactivity andrestorationofpre-CT estra-diollevels[17].Thesechangesinhormonallevelswouldbe expectedtoreduceorabolishtheefficacyoftheanticancer treatmentreceivedandexposepatientstofurtherunjustified side-effects, including pain from ovarian hyperstimulation andincreasedriskofunplannedpregnancy[18]. Confirma-tionofthemenopausalstatusis,therefore,mandatorybefore prescribingAI[19].

In currentclinicalpractice,menopauseinapatientwith CRA may be onlypresumed based on some clinical fea-tures, suchas age, the likelihoodof gonadal toxicityfrom chemotherapy, use of tamoxifen, menstrual history, vaso-motory symptoms,together withserumlevels of FSHand estradiol. Information obtained by these parameters, how-ever,maybemisleading.Inparticular,serumlevelsofFSH andestradiol,widelyusedtoconfirmmenopausalstatus,may provideerroneousinformationin25–35%ofcases[18,20].

Thisarticlereviewstheincidenceandthepathophysiology of gonadal damage induced by CT in womenaffected by endocrine-responsiveEBC.Moreover,practicalapproaches integratingnewmarkersof ovarianreserveareproposedto distinguishtrulymenopausalwomenwhomayreceiveanAI asadjuvantETfromthosewithCRA.

2. Ovarianinsufﬁciencyinducedbycytotoxicagents

2.1. Deﬁnitions

The progressive loss of oocytes from fetallife through menopauseisphysiological[21].Atapproximatelytheage of37,however,anacceleratedatresiaoftheoocytesis respon-siblefortheaverageageofmenopausebeingabout51years (range 40–60years)inWesternwomen[14,21,22]. Cessa-tionofmensesthatoccursbeforetheageof45isdefinedas “early”menopause.Whenmensesceaseevenearlier(before theageof40),itiscalled“premature”menopauseor prema-tureovarianfailure(POF).Thelatterisanarbitrarycut-off pointdesignatedbytheWorldHealthOrganization(WHO) correspondingtomenopauseoccurringatanagetwostandard deviationsbelowthepopulationmean[23].Instead,thereis noWHOproposeddefinitionforearlymenopause,whichis, however,largelyusedinseveralstudies.

(3)

F. T orino et al. / Critical Re vie ws in Oncolo gy/Hematolo gy 89 (2014) 27–42 29

Rateofchemotherapy-relatedamenorrheaandresumptionofmensesinselectedtrialsofcytotoxicchemotherapyincludingonlywomenaffectedbyearlybreastcancer.

Authors CTregimen No.patients CRAdefinition

(duration) Medianage (range;yrs) Medianfollow-up (range;mos) CRA(%) Resumptionof menses(%) <40yrs ≥40yrs Goldhirschetal.[56] CMF(400mg/mq,1) 541 <9mos NA NA 10 33 NA ClassicCMF×6 387 33 81 ClassicCMF×12 399 61 95

Venturinietal.[58] FEC21 250

>3mos NA 123(48–144) 64 NA FEC14 253 64 Jungetal.[70] CMF 188 ≥6mos 40(25–53) 109.8 (16.6–193) 43 12.5 FAC 53 65.2p=ns 3.3 Parulekaretal.[79] CMF 236 ≥3mos 43.8(23–55) 114(3–145) 71 NA CEF 224 76 p=ns DiCosimoetal.[60] CMF 19 ≥3mos 42(27–51) NA 47.4 Overall7.2 CMF-ED 10 58 FEC/EC 43 45.2 E/E-CMF 39 p=ns

Martinetal.[47] FAC 403

>3mos 49(23–70) 55

52.4

NA

TAC 420 61.7

p=.0007

Fornieretal.[49] AC-T 166 >12mos 36(27–40) 37.9(12.2–77.8) 15 85

Thametal.[45] AC 75

≥3mos NA NA

55 12

AC-T 116 64 28

p=ns p=ns

Berliereetal.[51] FEC 84

<12mos 43.5 79 92.5 23.7 FEC-D 70 44 93 36.5 p=ns p=.019

Pérez-Fidalgoetal.[53] A-based 212

≥12mos 44 NA 75.5 Overall6.3 TXs-based 93 43(29–53) 82.7 p=ns Ganzetal.[55] AT 752 ≥6mos 50 NA(6–24+) 47.1 NA TAC 705 51 67.2 AC-T 692 51 83.3 Petreketal.[61] AC 120 NA 39.5(20–45) NA(1–60+) 53 NA ACT 168 42 CMF 83 82 FAC 38 NA FACT 34 NA TAC 19 45 Sukumvanichetal.[62] CMF 76 ≥6mos 39(20–45) >24(6–60+) 34 23 (F)AC 146 37 68 (F)ACT 188 45 57 p=.002 Najafietal.[48] CMF 40 ≥6mos 40.9±6.8 36(12–120) 52.5 19.1 AC/CAF 111 66.7 27.1 ACT/AC-T 75 78.7 49.1

(4)

30 F. T orino et al. / Critical Re vie ws in Oncolo gy/Hematolo gy 89 (2014) 27–42 Table1(Continued)

Authors CTregimen No.patients CRAdefinition

(duration) Medianage (range;yrs) Medianfollow-up (range;mos) CRA(%) Resumptionof menses(%) <40yrs ≥40yrs

Leeetal.[52] AC/FAC 154

≥6mos 42(22–50) 37(12–80) 57 Overall14 FAC-T/ACT 148 58 CMF 24 56 p=ns Abusiefetal.[59] AC 228 ≥6mos 43(25–55) 33(6–114) 54.8 NA AC-T 183 56.4 AC-T(DD) 120 58.7 AC-T+H 39 46.1 Hanetal.[46] TXvsAC 122 >3mos 40(21–50) 40(18.8–69.3) 90.2 33.9 AC-T 34 73.5 23.2 FAC 129 72.1 p=ns

Zhouetal.[50] FEC 78

≥12mos 42.5(23–53) Mean 38.5(17–83) 44.9 NA TE 66 30.3 NE 26 23.1 Gerberetal.[64] AC±T 30 6mos 38.5(29–47) 24+ 93.3 56.7 AC±T+Goserelin 30 35(26–44) 83.3 70 p=.092 p=.284

Wongetal.[88] AC/EC±TXs/FEC+Goserelin 132

NA 35(20–45) 58(4–119) 91(<35yrs)

76(>35yrs)

Badawyetal.[89] FAC 39

NA 30±3.51 8(allpatients) 76.7 33.3 FAC+Goserelin 39 29.2±2.93 11.4 89.6 p=.76 p=.001

Munsteretal.[65] CT(AC±T/FEC/FAC) 21

NA 38(26–44) 18(5–43) 9.5 90.5 CT+Triptorelin 26 39(21–44 11.6 88.4 p=ns p=.36

DelMastroetal.[63] CTalone 133

CRM(§) 39(25–45) 24+ CRM 49.6 CT+Triptorelin 148 39(24–45) 25.9 63.3 8.9 p=.03 p<.001 Leonardetal.[90] A±C±TXs+Goserelin <40yrs:87

12 NA 12+_patients)(all

Noresumptionofmenses

>40yrs:53 34.7

15.8 p≤.05

Definitionofchemotherapy-relatedamenorrhea(CRA):absenceofmenseslastingfortheindicatedperiodoftime;A=adriamycin;AC:adriamycin,cyclophosphamide;AT:adriamycin,docetaxel;CMF: cyclophosphamide,methotrexate,5-fluorouracil;C=cyclophosphamide;CRM:chemotherapy-relatedmenopause;CEF:cyclophosphamide,epirubicin,5-fluorouracil;CT:cytotoxicchemotherapy;D=docetaxel; DD=dosedenseregimen;EC=epirubicin,cyclophosphamide;FAC:5-fluorouracil,adriamycin,cyclophosphamide;FACT:5-fluorouracil,adriamycin,cyclophosphamide,paclitaxel;FEC:5-fluorouracil, epirubicin,cyclophosphamide;mos=months;N=navelbine;NA=notavailable;TAC:docetaxel,adriamycin,cyclophosphamide;T=paclitaxel;TXs=taxanes;X=capecitabine;vs:versus;yrs=years.(§) CRM:noresumptionofmenstrualactivityandpostmenopausallevelsoffollicle-stimulatinghormoneandestradiol1yearafterthelastcycleofchemotherapy.

(5)

Table2

Estimated risk of permanent amenorrhea resulting from single agent chemotherapyandcombinationregimensusedasadjuvanttreatmentfor earlybreastcancer.

Singledrug Adjuvantregimens Highrisk(>80%) Cyclophosphamide

Ifosfamide Chlorambucil Melphalan, busulfan

•CMF,FEC,FAC×6cycles inwomenaged≥40years Nitrogenmustard

Procarbazine thiotepa

Intermediaterisk Cisplatin •CMF,FEC,FAC×6cycles inwomenaged30–39years Carboplatin

Adriamycin

•AC,EC×4inwomenaged ≥40years Taxanes •Taxane-containing combinations Lowrisk(<20%) ornorisk Bleomycin Dactinomycin

Vincristine •CMF,FEC,FAC×6cycles inwomenaged<30years Vinblastine

Methotrexate

Mercaptopurine •AC,EC×4inwomenaged <40years

5-Fluorouracil Tobedetermined Trastuzumab,

bevacizumab Lapatinib ModifiedfromRef.[107].

POFreferstoprimaryovarianinsufficiency,inwhichthe causeof ovariandysfunctionisinherent intheovary [24]. ThereisdebatewithintheliteratureastowhetherPOFshould referonlytospontaneouscessationofovarianfunctionand excludeinducedovarianfailure.

2.2. PathogenesisofPOFinducedbyCT

POFcausedbyCTcanarisethroughimpairmentof fol-licular maturationor primordial follicle depletion, or both

[3,25].Ovariesarevariablysensitivetomostcytotoxicdrugs (Table2)[26].Alkylatingagentsaremostcommonly asso-ciated with permanent and irreversible gonadal damage, presumablybecausethesedrugsarenotcellcycle-specific. Therefore, both resting and growing primordial follicles can be damaged [25,26]. Cycle-specific agents, such as methotrexate,5-fluorouracil,bleomycinandvincaalkaloids areassociatedwithmildornogonadotoxicity.Cisplatinand adriamycinmodestlyaffectovarianfunction.

Chemotherapy-inducedovariandamageresembles accel-eratedovarianaging[3,24,27].Pathologicfeaturesassociated withthistypeofPOFmainlyincludereductioninthe folli-clepool,withfollicularapoptosis,prematureatresia,harmed bloodvasculatureandcorticalfibrosis,eventuallyleadingto ovarianatrophy[27,28].

Currently, several mechanisms have been proposed to explain the damage induced by cytotoxic agents to the

ovaries,thoroughlyreviewedin[29,30]andsummarizedin

Table3.Presumably,differentclassesofanticancerdrugsact througharangeofmechanisms,possiblytargetingdifferent ovariancells[29].Oocyteapoptoticdeathcouldbethe con-sequenceofthedirectdamagetotheoocyteitself,tosomatic cells, or both.This, inturn,stimulatesprimordial follicles to grow to replace growing follicles, but reduces the pri-mordialpoolofrestingfollicles(the“burn-out”hypothesis)

[27]. Recently, acorrelation betweenacute vascular dam-ageandalterationinovarianbloodflow,size,andfunction, associated with an abnormal hormonal profile and clini-cal symptoms, was demonstratedin a small cohort of 20 premenopausal patients with EBC who were treated with neoadjuvant/adjuvantCT[31].Notably,theobservedpattern ofacuteovarianfailurewassimilarandhomogeneousinall patients,despiteageandvariabilityinCT-regimens.

2.3. ClinicalaspectsofPOF

The clinical degree of ovarian dysfunction (i.e., oligomenorrhea, transient/prolonged amenorrhea, and true menopause) is essentially related to the extent of injury causedbyCT.Oligomenorrheaortemporaryamenorrheaare theconsequenceof damagetobothsteroid-producingcells (granulosacellsandthecacells)andtheoocytesofgrowing follicles.WhenexposuretoCTinducesnearcomplete follic-ulardepletionorfewfolliclesremainviable(approximately <1000),periodsmayceaseandmenopausewilloccur[14,32]. Despitethefactthatmanypatients>40yearsofagedevelop CRA, ovarian failure may betemporary inaconsiderable numberofwomen.Itisnotyetknown whatpercentageof womenwithCRA/oligomenorrheawilllaterdevelopCRM. Theremainingfollicles,however,maystillberecruitedfrom theprimordial pool.Accordingly,gonadotropinlevelsmay returntonormal,menstrualcyclesmayresumeand/or fertil-itymayrecovermonthstoyearsafterwithdrawal/endofCT

[26].Mensesaremorelikelytoreturninyoungerwomen,in thosereceivinglessgonadotoxicregimensand,inanycase, inthosewithahigherbasalnumberoffollicles[12,14].

Women who continue to menstruate following CT-regimenmayhaveareducedlikelihoodofpregnancy,even ifmensesareregular[33–35].WomenwithtemporaryCRA present anincreased risk of CRM comparedtothosewho continuetomenstruatethroughouttreatment[36].

2.4. FactorspredictingtheonsetofPOFandresumption ofmensesinEBCpatients

Thelossorimpairmentofovarianfunctionassideeffects of adjuvant CT have been extensively studied in patients affectedbyEBC.In thesepatients, afewvariablesmainly influence the risk of POF induced by CT: the age of a patientwhenshecommencesCTandthetypeandthedoses of the prescribed CT [24,37,38]. Furthermore, tamoxifen may variably affect the onset of POF in premenopausal patients with endocrine-responsive EBC. Recently, the

(6)

32 F.Torinoetal./CriticalReviewsinOncology/Hematology89(2014)27–42 Table3

Overviewofpreclinicalpathogenicevidenceonovariantoxicityinducedbyanticancerdrugsavailableforthetreatmentofpatientsaffectedbybreastcancer.

Drugs Typesofovarycells

targeted

Mechanism(s)ofovariantoxicity/featuresofthedamage References Cyclophosphamide(alkylatingagenst?) Oocytes/PMF InhumanfetalovaryexposedtoCTX,apoptosiswas

shownbeforeinoocytes(PMF),thanGCs

[121] CTXmetabolitesinduceH2AX,amarkerofdouble

strandDNAbreakspredominantlyinmouseoocytes (butalsoinGCs)culturedinvitro

[122]

GCs IntheGCsofratovariesCTXdamagetomitochondria inducethereleaseofthecytocromeCintocytoplasm leadingtocellapoptosismediatedbycaspasefamily proteins.DamageinhumanGCsnucleiandfollicular basementmembranes

[32,33,122–129]

OxidativestresshasbeenassociatedwithCTXtoxicity inGCsofmaturefollicles.CTXinducesdepletionin glutathioneandriseinreactiveoxygenspecies mediatingapoptosisinGCs

Stromalcells/vessels Inhumanovariesseveresignsofstromalfibrosisand capillarychangesorcorticalfibrosisandbloodvessel damagewerefoundfollowingregimensincluding alkylatingagents

[34,35,130,131]

Platinumcompounds Oocytes/PMF Experimentalstudiesonplatinum-inducedovarian toxicitylimitedtocisplatin.Pre-granulosacell cytoplasmicandnuclearswellingfollowedbyPMF architecturedisruptionwithdisappearanceofthelumen anditsoocyte.Inratscisplatininducesreductionin ovulationrateandadeclineinAMHandinhibin-A

[27,126]

GCs/TCs Aftercisplatinexposure,declineinthelevelof hyperpolarization-activatedcationchannelsinrat oocytes,GCsandTCsmaycontributetodecreased ovarianfunction

[127,128]

Anotherproposedmechanismforcisplatin-induced ovariantoxicityistheaccumulationoforactivationof p63,amemberofp53family,eventuallyleadingto oocytedeath

[129]

Doxorubicin(anthracyclines) Oocytes/PMF Doxorubicininducesapoptosisinmammalianoocytes andsignificantlydecreasestheirsurvivalinvitro. Severalmolecularpathwaysareinvolvedinapoptosisof oocytes,includingdamagetochromosomes,activation ofmitochondriaandelevationofsuperoxidesthat inducesendoplasmicreticulumstresswiththeincrease inintracellularCa++_._This_cascade_in_turn_leads_to apoptosisviacalpainandcaspase12

[130–133]

GCs DNAdamageandapoptoticcelldeathinducedby doxorubicinhasbeendemonstratedbothinhuman primordialfolliclesandGCsinvitro

[134]

Stromalcells/vessels Acutereductioninovarianbloodflowanddisintegration ofthevesselwallfollowinginvivoadministrationof doxorubicin

[30,135]

Taxanes Maturefollicles Onlypreclinicalstudiesontaxane-inducedovarian toxicityareavailable,limitingtopaclitaxel.Thedrug inducesapoptosismainlyinmaturefolliclesandtoa lesserextentinlessmaturepopulations;alsoestradiol serumlevelswerereducedbythedrug

[136]

5-Fluorouracil Unknown Ovarianfunctioninmicemaybeaffected(reduced fertility)whenthedrugisadministeredduringthe immediatepostovulatoryphase,butnotduringtheother phasesoffertilitycycle

[137]

(7)

potentialroleofgeneticmarkerasapredictivefactorof ovar-iantoxicityhasemerged[28].Notably,comparisonsofPOF ratesbetweenstudiesarehamperedbysubstantial variabil-ity in treatment used, median age of patients, prevalence of endocrine-responsive disease, and follow-up duration. Inconsistenciesalsoexistinthemannerofreportingthe inci-dence of CRA, and evenin the definition of CRA. Some authorsreporttheincidenceofamenorrheauponcompletion ofchemotherapy,whileothersreportcontinuedamenorrhea atvariouspointsoftimeafterthestartofchemotherapy.In studiesonadjuvanttreatmentforBC,thedefinitionofCRA mayvaryfromtheabsenceofmensesforatleast3months tomorethan1year(Table1).

2.4.1. Age

Ageiscurrentlythemostrelevantbiologicalfactor influ-encingtheriskofCRM/CRA[12].TheoccurrenceofCRM inpatientswithEBChasbeenspecificallyevaluatedinvery fewstudies[39,40].Ithasbeenreportedin22–61%ofwomen aged<40and61–97%inthose>40years[3,39,41].Inthis group of patients, the incidence of CRA has been more extensivelyevaluated(Table1).Bymaintainingthearbitrary cut-offvalue of 40yearsof age, rates of CRAmayrange from49to100%inwomen>40years,andfrom10to71% inyoungerwomen[3,12].

Resumptionof menses(ReMen) inpatientsaffectedby EBCandCRAhasbeenreportedin11%ofthoseaged>40 yearsand22–56%ofthoseaged<40years,respectively[3]. Analysisof ReMeninthe IBCSGstudy VIpopulation(in which patients received 3–9 cycles of CMF) indicated a recoveryrateof43%inpatientsunder40,andof9%inthose aged40yearsandover[42].IntheNSABPB30study(708 patientsreceiving4cyclesofACand4cyclesofdocetaxel) ReMenoccurredwithin24monthsin45.3%ofpatientsaged under40,10.9%ofthoseaged40–50andin3.2%ofpatients agedover50[43].

2.4.2. Cytotoxicregimens

Other than age, the incidence of CRM/CRA mainly dependsonthetypeofCTandthescheduleof administra-tionused(Table1)[39,44].However,furtherfactorsrelated toCTdeliverymayinfluencetheonsetofPOF,includingthe combinationofmorethanonedrug(poly-CT),the cumula-tivedoseofalkylatingagents,andthephaseofthemenstrual cycle when CT isdelivered. In womencandidate to adju-vant CT for EBC,the most commonly used CT-regimens incorporatemultipleagentsthataregenerallyresponsiblefor amorenegativeimpactonovarianactivity,comparedwith monochemotherapy[3,26,39].Higher cumulative doses of alkylatingagentsareassociatedwiththehighestriskofCRM, particularlyinolderpremenopausalpatients[32,45,46]. Sim-ilarly, patients who received higher cumulative doses of cyclophosphamide,suchas withCMFandCEF/CAF-type regimens,showed ahigherrate oftransient andprolonged amenorrhea,comparedtoAC[3].Theinfluenceof taxanes onthe risk of CRA hasbeen evaluatedin severalstudies,

but remains controversial. When taxanes are added to standardregimens,theriskofCRAincreasesinthe major-ity of[45–50],butnot inall,trials [51–54].However, the extra-riskof CRAassociated withthesedrugs istransient, beinglimitedto12monthsfollowingtheendofCT.When CRArateswereevaluatedinacomparisonbetweenAC fol-lowed by docetaxel,TAC or AT, the latter regimenled to the lowest CRArate (69.8%, 57.7%, 37.9%, respectively)

[55].HigherdosesandlongerdurationofCT-regimensmay resultinhigherratesofCRA[56,57].Intwostudies evaluat-ing dose-denseFEC andAC-T,respectively, the incidence of CRA was identical in both the control and intensified arms (Table1) [58,59].However,definitive dataregarding theeffectofdose-densetherapyonratesofCRAarelacking. ThespecificimpactoftaxanesonthedevelopmentofCRM isstillunclear.Finally,whenCT-regimensareadministered duringthefollicularphaseofthemenstrualcycletheymay increasetheriskofovariantoxicity[3,12,60].

According to CT-regimen, ReMen may occur early or may be delayed even after 2–3 years from the onset of CRA.Inalargeprospectivestudyinvestigatingfactors affect-ing the maintenance of menstrual bleeding (595 patients affectedbyEBC;CT-regimens:FAC,AC±taxanesorCMF), women receiving CMF were more likely to bleed during the first month after chemotherapy than women on AC-containingregimens, but,byoneyearandthereafter,these women were less likely tobleed than thosewho received AC-regimens.Addingtaxanesresultedinafurtherreduction ofmonthlybleeding[61].Recently,thesamegroupreported results in a cohort of 466 premenopausal patients (20–45 years)receivingCT(AC/ACTorCMF)forEBC.Ofthese, 41% and29% experienced CRA, respectively, after 6 and 12months.Inbothgroups,approximately 50%ofpatients resumed bleeding within 3 years. ReMen differed signifi-cantlyaccordingtotreatment after 6 monthsof CRA(AC 68%, ACT57%,CMF23%), butnotafter oneyear.After 2-year CRA, none of the patients whohad receivedCMF experienced ReMen, compared with almost25% of those treatedwithAC-basedregimens[62].InthestudyofAbusief etal.[59],whichincluded 431patients treatedwith doxo-rubicin andcyclophosphamide,withor withoutpaclitaxel, ReMenbetween6and12monthsfollowingcompletionof chemotherapywasreportedin14%andafter>12monthsin anadditional3%ofcases.

Recently,anumberofPhaseIIITrialsevaluatedthe pro-tective role of gonadothropin-releasing hormone (GnRH) agonists in patients affected by EBC (see below). Since in these studies the primary end-point was the ovarian function after CT, the rates of CRA/CRM in the control group may represent a more reliable estimation of CT-induced ovarian toxicity. In a study by Del Mastro et al.

[63] on 281 patients (age≤45 years; CT-regimens were anthracycline-based, anthracycline plus taxane-based, or CMF-based±triptorelin),CRAandCRMrateswere75.5% and 25.9%, respectively. ReMen was reported by 49.6% of patients enrolledinthecontrol group[63].In thestudy

(8)

by Gerber et al. [64] on 60 patients under the age of 46 (CT-regimens:ACwithorwithouttaxane±goserelin),at6 monthsafterCTtherateoftemporaryCRAwas83.3%with ReMenin56.7%ofpatientsinthecontrolgroup.Lowerrates ofCRA/CRMwerereportedbyMunsteretal.[65].Inthis study,patients(44yearsoldor younger)weretreatedwith AC-TorFEC±triptorelin.After49patientswereenrolled, theaccrualwashaltedearlyduetofutility.However,inthe controlgrouptheratesofCRA,CRMandReMenwere24%, 10%and90%,respectively(medianfollow-upof18months fromcompletionofCT).Thedifferencesintermsofovarian toxicityshowedinthesetrialsmaybeexplainedbythe preva-lenceofyoungerpatients,thecumulativedoseofalkylating agentsdelivered andthe useof tamoxifen, butalsobythe differentdefinitionofamenorrhea,stratificationcriteriaand durationofthefollow-upperiod[66].

2.4.3. Endocrinetreatment

Tamoxifen isthe cornerstoneof endocrinetreatment of premenopausal patients affected by endocrine-responsive EBC. Premenopausal women receiving tamoxifenshowed areducedprobabilitytohavemonthlybleedingwithinone yearafterchemotherapy[79].Inlargeprospectivetrials,the use of this drug has been significantly associated withan increasedrateand/ordurationofCRA[39,42,43,66–69].In oneofthesestudies,theeffectofadjuvanttamoxifenonCRA appearedtobelimitedtowomen>40yearsofage[68]. Adju-vanttamoxifenfollowingCTforEBCappearedtoresultin aslightly,butstatisticallysignificant,increaseintheriskof CRM [3].Still, how tamoxifeninfluencesovarian toxicity remainsunclear.Thesuggestedmechanismsofinterference includethealterationofthehypothalamic-ovarianfeedback loopregulatingestrogensynthesisandhigherplasma estra-diollevels,duetotheselectiveestrogenreceptormodulation inducedbytamoxifen[35,70].

2.4.4. Geneticfactors

Ithasbeenproposedthatspecificgeneshavearolenot onlyindeterminingtheageofnatural menopause[71]but alsoinCRA/CRM[28].Inaprospectivestudyonacohortof 127youngBCsurvivors,acommonvariantofa cyclophos-phamide metabolizing enzyme (CYP3A4*1B) was found to be associated with higher risk of ovarian failure after cyclophosphamide-basedchemotherapycomparedwiththe wild-typegenotype[72].Thesedatashowthatgenetic mark-ers,otherthanageandcharacteristicsofCT-regimens,may have arole in predictingovarian toxicityinduced by CT. Furtherprospectivecorrelativetrialswillclarifytheclinical impactofthesenewpredictivebiomarkersoftoxicity.

3. TheprognosticsigniﬁcanceofCRA,CRMand

RMinpatientswithEBC

ApositiveinfluenceofCRAandCRMonthesurvivalof patientsaffectedbyEBChasbeenreportedinthemajority

ofstudies[12].Themechanismsunderlyingthebenefits of chemotherapyinendocrine-responsiveEBCpatients, how-ever, remain uncertain.Clinical evidencesuggeststhat CT mayexertadualmechanism:directcytotoxicactivityandan indirectsuppressivehormonaleffectmediatedbydamageto ovarianestrogen-producingcells[12,32].Thismayexplain theclinicalevidencethatchemotherapyismoreeffectivein younger,ratherthaninolder,patients.

In thelargestprospectivetrialevaluatingamenorrheaas a consequence of adjuvant CT-regimens (AT/ACT/AC-T) inpremenopausalEBCpatients,itwasinitiallyshownthat patients withCRA(definedaslackof menstruationfor>6 months during 24 months of follow-up) had significantly better overall anddisease-free survival thanthosewithout amenorrhea,regardlessoftreatment receivedand estrogen-receptorstatus[13,43].Inasubsequent12-monthlandmark analysis,the clinicalsignificanceof CRAwasfoundtobe restrictedtopatientswithER+disease[73].Thesedataare consistentwithresultsfromIBCSGTrial13–93andIBCSG TrialVIII,whereovarianfunctionsuppressionobtainedby CT (CRA)was associatedwithimprovedoutcome onlyin thesubgroupofpatientswithER+BC[74,75].

Whether prolongeddurationoftransientCRAresultsin survival advantagesis uncertain. In some studies, patients treatedwithanthracyclines/CMFshowedanimproved sur-vival benefit if they experienced amenorrhea, irrespective ofthetimeofonsetandduration[76,77].Inanotherstudy, womenwhoreceivedCMF/CEFshowedabettersurvivalrate iftheyhadachievedamenorrheaat12months,butnotat6 months [78].Interestingly, inarecent retrospective analy-sison872premenopausalpatients(medianageatdiagnosis: 41years,range,21–54)whoreceivedvariousCT-regimens for stage I–III BC, RM was significantly associated with shorter DFS (not OS) in both hormone receptor-positive and -negativepatients atmultivariate analysis [87].These results suggest that ReMen, more adequately than CRA, might reflect the endocrine-mediated anticancer effect of chemotherapy,atleastinpatients>35years[79].

4. Preservingfertilityinbreastcancerpatients

Infertility is among the major consequences of POF induced byCT[15].Issuesrelatedtoresidual fertility fol-lowingexposuretoCT-regimensareofmountingimportance due tothe rising tendencyby an increasing proportion of womentodelaypregnancytolaterinlife[15].Ithasbeen reportedthat morethan50% ofyoung womenhave fertil-ityconcernsuponbeingdiagnosedwithBC,andCT-induced infertilitymayinfluencetreatmentdecisionsinalmost30% ofyoungerBCpatients[80].Moreover,whethersubsequent pregnancy could increasethe risk of recurrence remainsa great concern in BC survivors, particularly in those with endocrine-responsive disease. This isdespite anumber of observationalstudiesthatshowednodetrimentaleffectsfrom pregnancyafterBC[13,42,73,78].

(9)

Anumberofeffectivemethodsareavailableforyounger BCpatientswishingtopreservetheirfertilitypotentialfrom damageofCT,includingcryopreservationtechniquesand/or theadministrationofGnRH-agonists[15,44].However,each ofthesemethodspresentsvariousprosandcontras. Meth-odsbasedoncryopreservationarecostly,complex,andhave asignificant failurerate [81,82].Both embryo andoocyte preservation techniques require ovarian stimulation before harvest.Thisexposespatientstohighestrogenlevels,a poten-tialrisk inpatients withER+BC. In addition,laparoscopy andgeneralanesthesiaarerequired,inducingadelayof2–6 weeksinstartingCT.Importantly,theefficacyofthese treat-mentsin patients>40 yearsof age seemsto be uncertain

[83].

TheuseofGnRHanalogshassomeadvantages.The treat-mentissimpletoadminister,islowincost,andCTneednot bedelayed.Moreover,amalepartnerisnotrequired.

However,GnRHagonistsmustbeadministeredoneweek tosixmonthsbeforeCTandcontinueuntiltheendofCT.Also thesafetyoftheuseofGnRHagonistsincancerpatientshas beenquestioned. SinceGnRHreceptorsareexpressedbya varietyofcancersandmediateseveraleffects(e.g.,inhibition of proliferation, induction of cell-cycle arrest, and inhibi-tionofapoptosis),ithasbeensuggestedthattheconcomitant administration of GnRHagonist therapymight antagonize CT, reducing its efficacy [84,85]. Therefore, ovarian sup-pressionwithGnRHagonistsmightbesaferinwomenwith estrogenreceptor-negative BC[86].Detrimental effects of GnRH agonists on patients under CT, however, were not showninclinicaltrials.

Moreover,resultsfromclinicaltrialsevaluatingthe effi-cacy of GnRH agonists in preventing CT-induced ovarian toxicityareconflicting.Arecentmeta-analysisincludingsix randomizedtrialsthat evaluatedovarian functionafter co-treatment with a GnRH agonist and various CT-regimens concludedthat thisapproachmaybebeneficial for protec-tionofmenstrualfunction[87].However,thetreatmentwith aGnRHagonistcombinedwithCTwasnotassociatedwith a statistically significant difference in the rate of sponta-neouspregnancyfollowingCT.Limitationsofthesefindings includedthe small sizeof mostof thetrials evaluated,the lackofadequateanalyzabledata,thegenerallyshortperiod offollow-up,methodologicalweaknessofoneofthetrials, andtheuseofdifferenttreatmentprotocols[87].

Morerecentstudieshavenotclarifiedtheissue.The pos-itiveroleofGnRH agonistsinpreservingovarian function duringchemotherapyforEBCpatientsissupportedbytwo trials,theItalianPROMISE-GIM6trial[63],andatrialfrom theRoyalMarsdenHospital,UK[88].Similarresultswere obtainedbyBadawyetal.[89]inasmallerstudy.Conversely, othersmallertrialsfailedtodemonstrateanybenefitofthe GnRHagonistsinpreservingfertilityinpatientswithEBC, includingtheZoladexRescueofOvarianFunction(ZORO) trial [64], the Ovarian Protection Trial in Estrogen Nega-tive(OPTION) [90]andthe study by Munsteret al.[65]. Resultsfromongoingstudiesaimedatevaluatingtheroleof

ovarian suppressioninpatients affectedbyEBC underCT (for example, thePrevention of Early MenopauseStudy– POEMS;SouthWestOncologyGroup-SWOGstudy0230) areawaited.

Finally,ithasbeensuggestedthattheconcomitantuseof GnRHagonistsforovariansuppressionandcryopreservation increasesthechancesofpreservingfertilityinyoungwomen

[44,88].

AccordingtoanupdateofAmericanSocietyofClinical Oncologypracticalguidelinesonfertilitypreservationin can-cerpatients,spermandembryocryopreservation,aswellas oocyte cryopreservation, are considered standard practice. Other fertility preservation methods should be considered investigationalandshouldbeperformed byproviderswith thenecessaryexpertise[91].

5. Measuringovarianreserveinhealthywomenand

inthosewithcancer

Ovarian reserve(OR)indicates the numberandquality of folliclesthat,atany givenage,are availabletoproduce adominant folliclelateinthefollicularphaseof the men-strual cycle. Several causes impair OR, including ovarian surgery,exposuretoviralorenvironmentaltoxicagentssuch as smoking, withanticancer CT or radiotherapy being the most common cause of acquired loss of OR [24]. How-ever, OR may be reduced in cancer patients at diagnosis

[24]. Similarly, ovarian response of patients who undergo controlledovarianhyperstimulationbeforeCTisdiminished evenbeforetreatment[92].Inalargecohortof40-year-old womennotundergoingsystemictreatment,anunusualearlier median ageof menopause onsetwasfound[93–95]. Con-versely,otherauthorsdidnotfindanyimpactofBConOR

[96]. Therefore, the real impact of cancer (particularlyof solid malignancies) onOR, andthe potential mechanisms of impairmentof ovarianfunctioninducedbycanceritself remaintobeclarified.

In the fertility andassisted reproduction setting,OR is measuredbyanumberofprocedures,suchasultrasound eval-uationoftheantralfolliclecount(AFC)andassessmentof serumlevelsofFSH,estradiol,inhibin-Bandanti-Müllerian hormone(AMH)[97].AMHisemergingasthemost promis-ing measure of OR. It is produced by the small growing folliclesandexertsaparacrineeffectontheprimordial fol-licle. AMH inhibitsthe recruitmentof primordial follicles intothegrowingfolliclepoolbyreducingsensitivitytoFSH. Conversely,inhibin-Bpositivelyinfluencesfolliculogenesis in the ovary (Fig. 1) [98]. AMH serum levels in normal cyclingwomendecline withageandbecomeundetectable inmenopausalwomen[99].Inseveralstudies,AMH accu-ratelyreflectstheovarianfolliclereserveandrepresentsthe mostsensitivemarkerfortheage-relateddeclineinthe num-berofprimordialfollicles.Inaddition,AMHandAFCoffer the most reliable assessment of the reproductive lifespan of the ovaries, as wellas of the risk of prematureovarian

(10)

Fig.1.Changingpatternsofhormoneproductionbyovarianfolliclesfrom restingtopre-ovulatorystages(darkershadinginhormonelabels corre-spondstogreaterhormoneproduction).Legend:TheriseinFSHserum levelsattheendofapreviousmenstrualcycledrivestheinitialfollicle recruit-ment.Growingfolliclesproduceestradiolandotherpeptidehormones,such asAMHandinhibin-B,whichareimportantinfeedbackregulationofFSH. AMHissecretedbypre-antralandantralfolliclesandappearedtoplay aninhibitingroleininitialrecruitmentofprimaryfolliclesfromthe res-tingprimordialfolliclepoolandintheselectionofthedominantfollicle, byreducingthesensitivityofantralfolliclesforFSH.Inhibin-Bmayhave paracrinefunctionspositivelyinfluencingfolliculogenesis.

failure.Moreover,theyarethebestpredictorsofthesuccess ofinvitrofertilizationcycles[97].

In women treated with chemotherapy for Hodgkin’s lymphoma,andinyoungwomenwhoreceived chemother-apy/radiotherapyforchildhoodcancer,[100–102]AMHwas themostsensitivepredictorofOR,comparedwithFSHand inhibin-B.

A limited number of studies evaluated OR in patients affectedbyEBCreceivingadjuvantCT/ET.Basal measure-mentsof AMH,FSH, inhibin-B,estrogen levelsandAFC havebeenfoundtobesensitivepredictorsofORinpatients with EBC undergoing CT [33,35,103]. Women still men-struatingaftertheendofCTpresent,however,higherFSH levels, lowerAMHand inhibin-B levels,as well as lower AFC,comparedtocontrols[35,103].LowerlevelsofAMH werestrictlyrelatedtoalowAFC,thuspredictingareduced likelihoodoffuturepregnancy[35].Highpretreatment lev-elsof AMHwereassociatedwithhighlevelsofAMHone yearaftercompletingtreatment[104].Furthermore,patients withpretreatmentlevels ofAMH abovethemedian ofthe studygroupshowedmorefavorablepost-treatmentovarian function,includingthosewithEBC[104].

AMHlevelsdecreaseafterthefirstcoursesof chemother-apyandprogressivelythereafterduringtreatment[34,104]. Inacohortof50premenopausalwomenwithEBC,itwas demonstrated that CT induced rapid decreases in AMH, inhibin-B,andAFC,withoutmodifyingestradiollevels[33]. Moreover,AMH levels prior tochemotherapywere lower inwomenwhobecameamenorrheicwithin6months, com-paredtothosewhoresumedmenses.Nosignificantdifference

inpretreatmentinhibin-Blevelswasfoundbetweengroups

[33]. On the other hand, it has been observed that pre-chemotherapy inhibin-B and AMH were lower inwomen with EBC who experienced CRA, both predicting CRA

[105].Likewise, in a cohort of 127 womenwho received adjuvant CT for EBC, AMH and inhibin-B were signif-icantly associated with the risk of CRA, compared with age-matched controls [102].AMH wassignificantlylower andFSH significantly higherinmenstruating womenwho developedsubsequent CRA[106].Conflictingresultshave beenreportedregardingtheinfluenceoftamoxifenonAMH andinhibin-B[33,35,106].

6. Whenarepatientswithchemotherapy-related

amenorrheaactuallymenopausal?

In healthy women,a few well defined clinical aspects (age,menstrualhistoryandmenopausalsymptoms)are gen-erallyindicativeofmenopausalstatus.Nevertheless,natural menopausecanonlyberetrospectivelyestablishedafter12 consecutive months of spontaneousamenorrhea, with bio-chemical confirmation of FSH and estradiol serum levels withinthemenopausalrange.

In studies assessingovarian functionfollowingCT, the definitionofmenopauseisheterogeneous[107].Inmostof these reports,the cessationof menses was theonly surro-gate marker of menopause, although the follow-up period was limited. According to the National Cancer Compre-hensive Network (NCCN) the diagnosis of menopause in BC patients should include any of the following criteria: prior bilateraloophorectomy; ageolderthan60years;age youngerthan60yearsandamenorrheafor≥12monthsinthe absenceofchemotherapy,tamoxifen,toremifene,orovarian suppression andFSH andestradiol in the postmenopausal range.Ifthepatientistakingtamoxifenortoremifene,and isunder60,thenFSHandplasmaestradiollevelsshouldbe inpostmenopausal ranges [10]. In theseguidelines,it was emphasizedthatforpremenopausalwomenstartingadjuvant ET, CRA isnot areliable indicator of menopausal status, as ovarian function may still be intact or resume despite chemotherapy-inducedanovulation/amenorrhea.Iftreatment withAI isforeseen, serial measurements of FSH/estradiol arerecommendedinpatientswithCRA[10].However,these factorsarenotcompletelyreliabletoconfirmmenopausein thesepatients[108].

Inparticular,biochemicaltestspresentanumberoflimits. Elevated FSH andreduced estradiol levels generally con-firm the clinical diagnosis of menopause. The duration of transitiontowardmenopause,however,ishighlyvariable,as it isadynamic continuum,withFSH/estradiolvalues sub-jecttowidefluctuation.Therefore,adiagnosticcut-off for thesebiomarkersisdifficulttodefine.Additionally,testing forFSH/estradiolonlyatsinglepointsintimeisnotsufficient toconfirmmenopause.Inthisrespect,serialassessmentsof thesebiomarkerswouldbemorereliable,butthenumberand

(11)

intervalsoftimepointsofassessmentremainarbitrary. More-over,when CTis used,the previsionof the definitiveloss ofovarianfunctionmaybemoreerratic.Inaddition,some technical aspects may negatively affect reliability of bio-chemicaltests.Currentplasmaestradiolradioimmunoassay isnotsufficientlysensitivetodetectthelowpostmenopause estradiollevels[109].Tandemmassspectrometry,avalidated methoddosingsteroidsinthepg/mlrange,maynotbewidely available[18].Furthermore,tamoxifenhasbeenreportedto increasecirculatingestrogensanddecreaseFSHlevels[110]. Increasedlevelsofestradiolmayresultfromcross-reactivity oftamoxifenanditsmetabolitesintheestradiolassay. Like-wise,exemestane,asteroidalAI,mayinterferewithserum estradiolmeasurement[111].AIprovokeastrongdecreasein estrogenlevelsandincreaseFSH levelsinpostmenopausal patients [110]. In premenopause,though, the inhibition of estrogenproductionis onlytemporary andthe subsequent FSHincreasemay,inturn,stimulatefolliculargrowth, aro-mataseproductionandrestorepre-CTestradiollevels[17].

Interestingly,AMHandinhibin-Bhaveshownapotential predictiveroleofovarianfunctionrecoveryinstudies eval-uating ORinlimited cohorts of cancerpatients, including thosewithBC.AMHlevels,inparticular,appeartoprovide apracticaltoolusefulindefiningtheindividualriskofPOF induced byCT [104].Conversely, inaretrospectivestudy onaveryyoungpopulationofwomenwhoreceivedCT/ET forEBC(medianage37years,range27–40),comparedwith age-matchedcontrols,neitherthebaselinenorchanging lev-elsinAMHappearedtobepredictivemarkersforsubsequent menstrualstatusfollowingCT[112].

Unfortunately,duetosomelimitationsinthesestudies,it isnotpossibletodefinetheroleofthesenewmarkersofOR aspredictivefactorsofCRM,especiallyinBCpatients.In fact,noneofthesestudieshasbeenspecificallydesignedto testAMH/inhibin-Baspredictive factorsof CRM;cohorts of patients are limited, the age distribution among the cohorts appears inhomogeneous, as does the treatment received,thedurationoffollow-upandthesamplecollection time.

Veryrecently,inaprospectivestudywitha5-yearmedian follow-up,basalserumAMHwasreportedtobestrongly pre-dictiveoflong-termovarianfunctioninacohortofpatients undergoingCT(±ET)for EBC[113].In particular,AMH remainedthe onlysignificant predictive factorof ORin a multivariateanalysisincludingageandFSH.

7. Ovarianreservemarkersandthechoiceof

endocrinetherapyinEBCpatients

Inclinicalpractice,ascertainingresidualovarianactivity inapremenopausalpatientwithendocrine-responsiveEBC andCRAisofkeyimportancenotonlytodefinethefertility potentialfollowingcompletionofCT,butalsotoselectthe appropriateadjuvantET(tamoxifenversusAI)[114].Tothis aim,AMHmaybeusedassuggestedinFig.2.

Fig.2.Practicalapproachessuggestedwhenaromataseinhibitorsarethe preferredendocrinestrategyforpatientswithendocrine-responsiveEBC andCRAoramenorrheaundertamoxifen. Abbreviations:AI,aromatase inhibitor; AMH,anti-Müllerian hormone; CRA, chemotherapyinduced amenorrhea;E2,estradiol;EBC,earlybreastcancer;ET,endocrine ther-apy;FSH,follicle-stimulatinghormone;OFS,ovarianfunctionsuppression (oophorectomyorchemicalsuppressionwithagonadotropin-releasing hor-moneagonist);TAM,tamoxifen

Womenundertheageof40generallymaintain residual OR following CT,despite persistent CRA, and, therefore, they should not receive an AI as the only adjuvant ET. Ifestrogendepletionisthedesiredendocrinestrategy,this shouldincludeovarianfunctionsuppression(OFS; oophorec-tomyorchemicalsuppressionwithagonadotropin-releasing hormone agonist) in combination with tamoxifen [9,10]. Alternatively,enteringaclinicaltrialisanadvisableoption. Women over the age of 40 who have developed CRA or amenorrheaduringtamoxifenshouldmeasure FSHand estradiol,preferablywithahigh-qualityestradiolassay(i.e., massspectrometry),whichallowsahighsensitivity(inthe order of pg/ml) together witha high-specificity (no cross reactionwithothersteroidalmolecules)[115].Womenwith levelswithin thepremenopausalrange (i.e.,FSH<30UI/L andestradiol>20pmol/L), shouldreceivetamoxifenalone ortamoxifen+OFS.

If intermediate hormone levels (FSH: 30–40UI/L and estradiol:10–20pg/ml)appeartobeindicativeofmenopausal transition/perimenopause, measuring AMH levels may be useful in detecting residual ovarian activity [113]. If FSH/estradiol levels are consistent with menopause (FSH>40UI/L andestradiol<10pmol/L),AImaybe pre-scribed. However, basal and serial hormone monitoring shouldbeperformed(e.g.,every4months),andAMHlevels shouldbeprudentiallymeasuredeveninthisgroup.

Since CRA may be a reversible condition especially in youngerwomen, patients underAI whoexperience the occurrenceof certainsymptoms,suchastheonsetof vagi-nal bleedingorthe suddencessationofhot flashes,should be rapidly referred to the clinician [18]. Similarly, sexu-ally activewomenwithCRAneedtobecounseledfor the

(12)

maintenanceofbirthcontrol,giventhattheymayovulateand, therefore,becomepregnant,despitetheabsenceofmenses.

8. Conclusions

Ovarian toxicity is a major concern of young cancer patientswhoneedCTfor acure. Thereductioninfertility potentialinducedbyCT-regimensshouldbetakeninto con-siderationinfamilyplanningdecisionsthroughoutdiagnosis andfollow-up,andeffectiveapproachesaimedatpreserving ovarianfunctionshouldberegularlyofferedtowomenwho needtoreceiveCTandET[5,34,63,91,116].However,since cryopreservationofembryosoroocytesrequirescontrolled ovarianstimulation,theriskofincreasedpeakestradiol lev-elswiththisstrategyinpatients withendocrine-responsive EBC should be discussed before the procedure. The con-trolledovarian stimulation using tamoxifenor letrozole in conjunctionwithgonadotropinmaybesaferforwomenwith endocrine-responsiveBC[116].

Evaluation of OR in cancer patients may be challeng-ing,and,therefore,availabilityofpredictorsprovidingmore reliableassessmentsofovarianfunctionisofmajorclinical importance.Atpresent,AFC,AMHandinhibin-Bare reli-ablepredictive factors of fertility,evenin cancerpatients. Ongoing largeprospective trials will define which values of the availableparametersassessingOR areindicative of irreversiblelossofovarianfunction(i.e.,thetruemenopausal status)inwomenwithendocrine-responsiveEBCandCRA. However, in a multidisciplinary evaluation with endocri-nologists, acareful use of AMH values may improve the assessmentof residualORand,therefore,of CRM, partic-ularly in a specific subset of women, such as those with endocrine-responsive EBC, CRA and uncertain values of FSH/estradiol.

Furtherinvestigationsaimedatestablishingtheeffectson ovarian functionof newercytotoxic regimenswould offer effectivealternativetreatmentswithlessovariantoxicity.A deeperknowledgeofpotentialmechanismssustaining ovar-iantoxicitytriggeredbyspecificdrugsremainstherational approachtoselectthemostsuitablestrategytoprevent ovar-iantoxicity.

Conﬂictofinterest

The authors declarethat thereis no conflictof interest thatcouldbeperceivedasprejudicingtheimpartialityofthe researchreported.

Funding

Nofundswererequestedfromanypharmaceuticalfirms or other industries/institutions. Valentina Sini is financed through the PhD University Grant program “Clinical and Experimental Research Methodologies in Oncology”

provided by the Faculty of Medicine and Psychology, “Sapienza”UniversityofRome.

Reviewers

Dr.PierFrancoConte,Director,UniversityHospital, Mod-ena, Department of Oncology and Hematology, Via Del Pozzo,71,I-41100Modena,Italy.

Dr.LuciaDelMastro,UOSviluppoTerapieInnovative, OncologiaMedicaA,IRCCSAOUSanMartino-IST,Istituto NazionaleperlaRicerca,sulCancro,L.goR.Benzi10, I-16132Genova,Italy.

Dr. Giampaolo Papi, Department of Internal Medicine, SectionofEndocrinology,UniversityofModenaandReggio Emilia,Modena,Italy.

References

[1]AmericanCancerSociety,BreastCancerFacts&Figures,2011–2012 www.cancer.org/Research/CancerFactsFigures/ACSPC-031941 [2]SiegelR,NaishadhamD,JemalA.Cancerstatistics,2012.CA:A

CancerJournalforClinicians2012;62:10–29.

[3]BinesJ,OleskeD,CobleighM.Ovarianfunctioninpremenopausal womentreatedwithadjuvantchemotherapyforbreastcancer.Journal ofClinicalOncology1996;14:1718–29.

[4]SamphaoS,WheelerAJ,RaffertyE,etal.Diagnosisofbreast can-cerinwomenage40andyounger:delaysindiagnosisresultfrom underuseofgenetictestingandbreastimaging.AmericanJournalof Surgery2009;198:538–43.

[5]CardosoF,LoiblS,PaganiO,etal.EuropeanSocietyofBreast Can-cerSpecialists.TheEuropeanSocietyofBreastCancerSpecialists recommendationsforthemanagementofyoungwomenwithbreast cancer.EuropeanJournalofCancer2012;48:3355–77.

[6]FredholmH,EakerS,FrisellJ,HolmbergL,FredrikssonI,Lindman H.Breastcancerinyoungwomen:poorsurvivaldespiteintensive treatment.PLoSONE2009;4:e7695.

[7]SwansonGM,LinCS.Survivalpatternsamongyoungerwomenwith breastcancer:theeffectsofage,race,stage,andtreatment.Journalof theNationalCancerInstituteMonographs1994;16:69–77. [8]ColleoniM,RotmenszN,RobertsonC,etal.Veryyoungwomen(<35

years)withoperablebreastcancer:featuresofdiseaseatpresentation. AnnalsofOncology2002;13:273–9.

[9]GoldhirschA,WoodWC,CoatesAS,etal.Strategiesfor subtypes-dealingwiththediversityofbreastcancer:highlightsoftheStGallen InternationalExpert ConsensusonthePrimaryTherapyofEarly BreastCancer2011.AnnalsofOncology2011;22:1736–47. [10]NationalComprehensiveCancerNetwork–BreastCancer

Guide-lines;2013.www.nccn.org(accessedFebruary2013).

[11]Early Breast Cancer Trialists’ Collaborative Group. Effects of chemotherapyandhormonaltherapyforearlybreastcanceron recur-renceand15-yearsurvival:an overviewoftherandomisedtrials. Lancet2005;365:1687–717.

[12]WalsheJ,Denduluri N,SwainS.Amenorrheain pre-menopausal womenafteradjuvantchemotherapyforbreastcancer.Journalof ClinicalOncology2006;24:5769–79.

[13]SwainSM,JeongJH,GeyerJrCE,etal.Longertherapy,iatrogenic amenorrhea,andsurvivalinearlybreastcancer.NewEnglandJournal ofMedicine2010;362:2053–65.

[14]SchoverLR.Prematureovarianfailureanditsconsequences: vasomo-torsymptoms,sexuality,andfertility.JournalofClinicalOncology 2008;26:753–8.

(13)

[15]RuddyKJ,PartridgeAH.Fertility(maleandfemale)andmenopause. JournalofClinicalOncology2012;30:3705–11.

[16]BursteinHJ,PrestrudAA,SeidenfeldJ,etal.AmericanSocietyof ClinicalOncology clinicalpracticeguideline:updateonadjuvant endocrinetherapyforwomenwithhormonereceptor-positivebreast cancer.JournalofClinicalOncology2010;28:3784–96.

[17]de ZieglerD,MattenbergerC, LuyetC,RomoscanuI, IrionNF, Bianchi-DemicheliF.Clinicaluseofaromataseinhibitors(AI)in pre-menopausalwomen.JournalofSteroidBiochemistryandMolecular Biology2005;95:121–7.

[18]SmithIE,DowsettM,YapYS,etal.Adjuvantaromataseinhibitors for early breast cancer after chemotherapy-induced amenorrhea: caution and suggested guidelines. Journal of Clinical Oncology 2006;24:2444–7.

[19]OrtmannO,PaganiO,JonesA,etal.Whichfactorsshouldbetaken intoaccountinperimenopausalwomenwithearlybreastcancerwho maybecomeeligibleforanaromataseinhibitor?Recommendations ofanexpertpanel.CancerTreatmentReviews2011;37:97–104. [20]HenryNL,BanerjeeM,HaydenJ,etal.PredictorsofRecoveryof

OvarianFunctionduringAromataseInhibitor(AI)Therapy.Cancer Research2011;71(Suppl.3)[abstractPD04-01].

[21]FaddyMJ,GosdenRG,GougeonA,RichardsonSJ,NelsonJF. Accel-erated disappearanceofovarianfolliclesinmid-life:implications forforecastingmenopause.HumanReproduction(Oxford,England) 1992;10:1342–6.

[22]GougeonA,EcochardR,ThalabardJC.Age-relatedchangesofthe populationofhumanovarianfollicles:increaseinthedisappearance rateofnon-growing andearly-growing folliclesin agingwomen. BiologyofReproduction1994;50:653–63.

[23]CoulamCB,AdamsonSC,AnnegersJF.Incidenceofpremature ovar-ianfailure.ObstetricsandGynecology1986;67:604.

[24]DeVosM,DevroeyP,FauserBCJM.Primaryovarianinsufficiency. Lancet2010;376:911–21.

[25]ChapmanR.Effectofcytotoxictherapyonsexualityandgonadal function.SeminarsinOncology1982;9:84–94.

[26]SonmezerM,OktayK.Fertilitypreservationinyoungwomen under-goingbreastcancertherapy.Oncologist2006;11:422–34.

[27]MeirowD,BiedermanH,AndersonRA,WallaceWH.Toxicityof chemotherapyandradiationonfemalereproduction.Clinical Obstet-ricsandGynecology2010;53:727–9.

[28]Meirow D. Reproduction post-chemotherapy in young can-cer patients. Molecular and Cellular Endocrinology 2000;169 (November):123–31.

[29]MorganS,AndersonRA,GourleyC,WallaceWH,SpearsN.How dochemotherapeuticagentsdamagetheovary?HumanReproduction Update2012;18:525–35.

[30]Ben-AharonI,ShalgiR.Whatliesbehindchemotherapy-induced ovariantoxicity?Reproduction2012;144:153–63.

[31]Ben-AharonI,MeiznerI,GranotT,etal.Chemotherapy-induced ovarianfailureasaprototypeforacutevasculartoxicity.Oncologist 2012;17:1386–93.

[32]Partridge AH, Ruddy KJ. Fertility and adjuvant treatment in young women with breast cancer. Breast 2007;16(Suppl. 2): 175–81.

[33]AndersonRA,ThemmenAP,Al-QahtaniA,GroomeNP,Cameron DA.Theeffectsofchemotherapyandlong-termgonadotrophin sup-pressionontheovarianreserveinpremenopausalwomenwithbreast cancer.HumanReproduction2006;21:2583–92.

[34]Oktay K,OktemO,Reh A,VahdatL. Measuringtheimpactof chemotherapyonfertilityinwomenwithbreastcancer.Journalof ClinicalOncology2006;24:4044–6.

[35]PartridgeAH,RuddyKJ,GelberS,etal.Ovarianreserveinwomen whoremainpremenopausalafterchemotherapyforearlystagebreast cancer.FertilityandSterility2010;94:638–44.

[36]GanzPA,GreendaleGA,PetersenL,KahnB,BowerJE.Breastcancer inyoungerwomen:reproductiveandlatehealtheffectsoftreatment. JournalofClinicalOncology2003;21:4184–93.

[37]StearnsV,SchneiderB,HenryNL,HayesDF,FlockhartDA.Breast cancertreatmentandovarianfailure:riskfactorsandemerginggenetic determinants.NatureReviewsCancer2006;6:886–93.

[38]JerussJS,WoodruffTK.Preservation offertilityinpatients with cancer.NewEnglandJournalofMedicine2009;360:902–11. [39]GoodwinPJ,EnnisM,PritchardKI,TrudeauM,HoodN.Riskof

menopauseduringthefirstyearafterbreastcancerdiagnosis.Journal ofClinicalOncology1999;17:2365–70.

[40]PadmanabhanN,HowellA,RubensRD.Mechanismofactionof adjuvantchemotherapyinearlybreastcancer.Lancet1986;23:411–4. [41]Del Mastro L, Venturini M,Sertoli MR, Rosso R. Amenorrhea inducedbyadjuvantchemotherapyinearlybreastcancerpatients: prognosticroleandclinicalimplications.BreastCancerResearchand Treatment1997;43:183–90.

[42]PaganiO,O’NeillA,CastiglioneM,etal.Prognosticimpactof amen-orrhoeaafteradjuvantchemotherapyinpremenopausalbreastcancer patientswithaxillarynodeinvolvement:resultsoftheInternational BreastCancerStudyGroup(IBCSG)TrialVI.EuropeanJournalof Cancer1998;34:632–40.

[43]SwainSM,LandSR,RitterMW,etal.Amenorrheainpremenopausal women on the doxorubicin-and-cyclophosphamide followed by-docetaxelarmofNSABPB-30trial.BreastCancerResearchand Treatment2009;113:315–20.

[44]DelMastroL,GiraudiS,LevaggiA,PronzatoP.Medicalapproaches topreservationoffertilityinfemalecancerpatients.ExpertOpinion onPharmacotherapy2011;12:387–96.

[45]ThamYL,SextonK,WeissH,ElledgeR,FriedmanLC,KramerR. Theratesofchemotherapyinducedamenorrheainpatientstreated withadjuvantdoxorubicinandcyclophosphamidefollowedbya tax-ane.AmericanJournalofClinicalOncology2007;30:126–32. [46]HanHS,RoJ,LeeKS, etal.Analysisofchemotherapy-induced

amenorrhearatesbythreedifferentanthracyclineandtaxane con-tainingregimensforearlybreastcancer.BreastCancerResearchand Treatment2009;115:335–42.

[47]Martin M, Pienkowski T, Mackey J, et al. Adjuvant docetaxel fornode-positivebreastcancer.NewEnglandJournalofMedicine 2005;352:2302–13.

[48]Najafi S,Djavid GE,Mehrdad N, etal. Taxane-based regimens asariskfactorforchemotherapy-inducedamenorrhea.Menopause 2011;18:208–12.

[49]FornierMN,ModiS,PanageasKS,NortonL,HudisC.Incidenceof chemotherapy-induced,long-termamenorrheainpatientswithbreast carcinomaage40yearsandyoungerafteradjuvantanthracyclineand taxane.Cancer2005;104:1575–9.

[50]ZhouWB,YinH,LiuXA,etal.Incidenceofchemotherapy-induced amenorrheaassociatedwithepirubicin,docetaxelandnavelbinein youngerbreastcancerpatients.BMCCancer2010;10:281. [51]BerliereM,DalencF,MalingretN,etal.Incidenceofreversibile

amenorrea in women with breast cancer undergoing adjuvant anthracycline-basedchemotherapywithorwithoutdocetaxel.BMC Cancer2008;8:56.

[52]Lee S, Kil WJ, Chun M, et al. Chemotherapy-related amenor-rhea in premenopausal women with breast cancer. Menopause 2009;16:98–103.

[53]Pérez-Fidalgo JA, Roselló S, García-Garré E, et al. Incidence ofchemotherapy-inducedamenorrhea inhormone-sensitivebreast cancerpatients:theimpactofadditionoftaxanesto anthracycline-basedregimens.BreastCancerResearchandTreatment2010;120: 245–51.

[54]OkanamiY,ItoY,WatanabeC,etal.Incidenceof chemotherapy-inducedamenorrhea inpremenopausalpatientswithbreastcancer following adjuvant anthracycline and taxane. Breast Cancer 2011;18:182–8.

[55]GanzPA,LandSR,GeyerJrCE,etal.Menstrualhistoryand quality-of-lifeoutcomesinwomenwithnode-positivebreastcancertreated withadjuvanttherapyontheNSABPB-30trial.JournalofClinical Oncology2011;29:1110–7.

(14)

40 F.Torinoetal./CriticalReviewsinOncology/Hematology89(2014)27–42 [56]GoldhirschA,GelberRD,CastiglioneM.Themagnitudeofendocrine

effectsofadjuvantchemotherapyforpremenopausalbreastcancer patients.TheInternationalBreastCancerStudyGroup.Annalsof Oncology1990;1:183–8.

[57]BasserRL,O’NeillA,MartinelliG,etal.Multicycledose-intensive chemotherapyforwomenwithhigh-riskprimarybreastcancer:results ofInternationalBreastCancerStudyGroupTrial15-95.Journalof ClinicalOncology2006;24:370–8.

[58]Venturini M,Del MastroL,AitiniE, etal.Dose-denseadjuvant chemotherapyinearlybreastcancerpatients:resultsfroma random-izedtrial.JournaloftheNationalCancerInstitute2005;97:1724–33. [59]AbusiefME,MissmerSA,GinsburgES,WeeksJC,PartridgeAH. Theeffectsofpaclitaxel,dosedensity,andtrastuzumabon treatment-relatedamenorrhea in premenopausal womenwith breastcancer. Cancer2010;116:791–8.

[60]Di Cosimo S, Alimonti A, Ferretti G, et al. Incidence of chemotherapy-inducedamenorrheadependingonthetimingof treat-mentbymenstrualcyclephaseinwomenwithearlybreastcancer. AnnalsofOncology2004;15:1065–71.

[61]PetrekJA,NaughtonMJ,CaseLD,etal.Incidence,timecourse,and determinantsofmenstrualbleedingafterbreastcancertreatment:a prospectivestudy.JournalofClinicalOncology2006;24:1045–51. [62]SukumvanichP,CaseLD,VanZeeK,etal.Incidenceandtimecourse

ofbleedingafterlong-termamenorrheaafterbreastcancertreatment: aprospectivestudy.Cancer2010;116:3102–11.

[63]DelMastroL,BoniL,MichelottiA,etal.Effectofthe gonadotropin-releasing hormone analogue triptorelin on the occurrence of chemotherapy-induced earlymenopauseinpremenopausalwomen withbreastcancer:arandomizedtrial.JournaloftheAmerican Med-icalAssociation2011;306:269–76.

[64]GerberB,vonMinckwitzG,StehleH,etal.Effectofluteinizing hormone–releasinghormoneagonistonovarianfunctionafter mod-ernadjuvantbreastcancerchemotherapy:theGBG37ZOROstudy. JournalofClinicalOncology2011;29:2334–41.

[65]MunsterPN,MooreAP,Ismail-KhanR,etal.Randomizedtrialusing gonadotropin-releasinghormoneagonisttriptorelinforthe preserva-tionofovarianfunctionduring(neo)adjuvantchemotherapyforbreast cancer.JournalofClinicalOncology2012;30:533–8.

[66]Partridge AH. Ovarian suppression for prevention of premature menopauseandinfertility:emptypromiseoreffectivetherapy? Jour-nalofClinicalOncology2012;30:479–81.

[67]Boccardo F, Rubagotti A,Bruzzi P, et al.Chemotherapy versus tamoxifen versus chemotherapy plustamoxifen in node-positive, estrogenreceptor-positivebreastcancerpatients:resultsofa multicen-tricItalianstudy.BreastCancerAdjuvantChemo-HormoneTherapy CooperativeGroup.JournalofClinicalOncology1990;8:1310–20. [68]Jordan VC, Fritz NF, Langan-Fahey S, Thompson M, Tormey

DC.Alterationofendocrineparametersinpremenopausalwomen withbreastcancerduringlong-termadjuvanttherapywith tamox-ifenas thesingleagent.Journal oftheNationalCancerInstitute 1991;83:1488–91.

[69]ColleoniM,GelberS,GoldhirschA,etal.Tamoxifenafteradjuvant chemotherapyforpremenopausalwomenwithlymphnode-positive breastcancer:InternationalBreastCancerStudyGroupTrial13-93. JournalofClinicalOncology2006;24:1332–41.

[70]Jung M, Shin HJ, Rha SY, et al. The clinical outcome of chemotherapy-inducedamenorrheainpremenopausalyoungpatients with breastcancer with long-term follow-up.Annalsof Surgical Oncology2010;17:3259–68.

[71]RoseD,DavisT.Effectsofadjuvantchemohormonaltherapyon theovarianandadrenalfunctionofbreastcancerpatients.Cancer Research1980;40:4043–7.

[72]Stolk L,Zhai G,van MeursJB,etal.Lociatchromosomes 13, 19 and 20 influence ageat natural menopause.Nature Genetics 2009;41:645–7.

[73]SuHI,Sammel MD,VeldersL, etal.Association of cyclophos-phamide drug-metabolizing enzyme polymorphisms and

chemotherapy-related ovarian failure in breast cancer survivors. FertilityandSterility2010;94:645–54.

[74]SwainSM,JeongJH,WolmarkN.Amenorrheafrombreastcancer therapy—notamatterofdose.NewEnglandJournalofMedicine 2010;363:2268–70.

[75]InternationalBreastCancerStudyGroup.Tamoxifenafteradjuvant chemotherapyforpremenopausalwomenwithlymphnode-positive breastcancer:InternationalBreastCancerStudyGroupTrial13-93. JournalofClinicalOncology2006;24:1332–41.

[76]KarlssonP,SunZ, BraunD,etal.Longtermresultsof Interna-tionalBreastCancerStudyGroupTrialVIII:adjuvantchemotherapy plusgoserelincomparedwitheithertherapyaloneforpremenopausal patients with node-negative breast cancer. Annals of Oncology 2011;22:2216–26.

[77]BiancoAR,DelMastroL,GalloC,etal.Prognosticroleof amen-orrheainducedbyadjuvantchemotherapyinpremenopausalpatients withearlybreastcancer.BritishJournalofCancer1991;63:799–803. [78]ReynoLM,LevineMN,SkingleyP,SkingleyP,ArnoldA,AbuZahra H.Chemotherapyinducedamenorrhoeainarandomisedtrialof adju-vantchemotherapydurationinbreastcancer.EuropeanJournalof Cancer1993;29:21–3.

[79]Parulekar WR, Day AG, Ottaway JA,et al.Incidence and pro-gnosticimpactofamenorrheaduringadjuvanttherapyinhigh-risk premenopausalbreastcancer:analysisofaNationalCancerInstitute ofCanadaClinicalTrialsGroupStudy-NCICCTGMA.5.Journalof ClinicalOncology2005;23:6002–8.

[80]ParkIH,HanHS,LeeH,etal.Resumptionorpersistenceof men-struationaftercytotoxicchemotherapyisaprognosticfactorforpoor disease-freesurvivalinpremenopausalpatientswithearlybreast can-cer.AnnalsofOncology2012;23:2283–9.

[81]PartridgeAH,GelberS,PeppercornJ,etal.Web-basedsurveyof fertilityissuesinyoungwomenwithbreastcancer.JournalofClinical Oncology2004;22:4174–83.

[82]LucernaE,BernalDP,LucernaC,RojasA,MoranA,LucenaA. Successfulongoingpregnanciesaftervitrificationofoocytes.Fertility andSterility2006;85:108–11.

[83]DolmansMM,DonnezJ,CamboniA,etal.IVFoutcomeinpatients withorthotopicallytransplantedovariantissue.HumanReproduction 2009;24:2778–87.

[84]VitaleAM,AbramovichD,PeluffoMC,MeresmanG,TesoneM. Effectofgonadotropin-releasinghormoneagonistandantagoniston proliferationandapoptosisofhumanluteinizedgranulosacells. Fer-tilityandSterility2006;85:1064.

[85]EmonsG,GründkerC,GünthertAR,WestphalenS,KavanaghJ, VerschraegenC.GnRHantagonistsinthetreatmentofgynecological andbreastcancers.EndocrineRelatedCancer2003;10:291. [86]RugoHS,RosenMP.Reducingthelong-termeffectsof

chemother-apyinyoungwomenwithearly-stagebreastcancer.Journalofthe AmericanMedicalAssociation2011;306:312.

[87]Bedaiwy MA, Abou-Setta AM, Desai N, et al. Gonadotropin-releasinghormoneanalogcotreatmentforpreservationofovarian functionduringgonadotoxicchemotherapy:asystematicreviewand meta-analysis.FertilityandSterility2011;95:906.

[88]WongM,O’NeillS,WalshG,SmithIE.Goserelinwith chemother-apy topreserve ovarian functionin pre-menopausalwomen with earlybreastcancer:menstruationandpregnancyoutcomes.Annals ofOncology2013;24:133–8.

[89]Badawy A, Elnashar A, El-Ashry M,Shahat M. Gonadotropin-releasinghormoneagonistsforpreventionofchemotherapy-induced ovariandamage:prospectiverandomizedstudy.FertilityandSterility 2009;91:694–7.

[90]LeonardRC,AdamsonD,AndersonR,etal.TheOPTIONtrialof adjuvantovarianprotectionbygoserelininadjuvantchemotherapyfor earlybreastcancer.JournalofClinicalOncology2010;28:89s[Suppl. 15;abstr590].

[91]LorenAW,ManguPB,BeckLN,etal.Fertilitypreservationfor patientswithcancer:AmericanSocietyofClinicalOncologyClinical

(15)

PracticeGuidelineupdate.JournalofClinicalOncology2013;May, http://dx.doi.org/10.1200/JCO.2013.49.2678.

[92]DomingoJ,GuillénV,AyllónY,etal.Ovarianresponsetocontrolled ovarianhyperstimulationincancerpatientsisdiminishedevenbefore oncologicaltreatment.FertilityandSterility2012;97:930–4. [93]Mertens A, Yasui Y, Neglia J, et al. Late mortality experience

in five-year survivors of childhood and adolescent cancer: the childhood cancer survivor study. Journal of Clinical Oncology 2001;19:3163–72.

[94]PartridgeA,GelberS,GelberRD,Castiglione-GertschM, Gold-hirschA,WinerE.Ageofmenopauseamongwomenwhoremain premenopausalfollowingtreatmentforearlybreastcancer:long-term resultsfromInternationalBreastCancerStudyGroupTrialsVand VI.EuropeanJournalofCancer2007;43:1646–53.

[95]Lawrenz B, Fehm T, von Wolff M, et al. Centers of Fer-tiPROTEKT Network. Reduced pretreatment ovarian reserve in premenopausal femalepatients with Hodgkinlymphoma or non-Hodgkin-lymphoma—evaluation by using antimüllerian hormone andretrievedoocytes.FertilityandSterility2012;98:141–4. [96]SuHI,FlattSW,Natarajan L,DeMicheleA,SteinerAZ.Impact

ofbreastcanceronanti-mullerianhormonelevelsinyoungwomen. BreastCancerResearchandTreatment2013;137:571–7.

[97]Lambalk CB, van Disseldorp J,de Koning CH, Broekmans FJ. Testing ovarian reserve to predict age at menopause. Maturitas 2009;63:280–91.

[98]FindlayJK,DrummondAE,BrittKL,etal.Therolesofactivins, inhibinsandestrogeninearlycommittedfollicles.Molecularand CellularEndocrinology2000;163:81–7.

[99]deVetA,LavenJS,deJongFH,ThemmenAP,FauserBC. Anti-mullerianhormoneserumlevels:aputativemarkofovarianaging. FertilityandSterility2002;77:357–62.

[100]BathLE,WallaceWH,ShawMP,FitzpatrickC,AndersonRA. Deple-tionofovarianreserveinyoungwomenaftertreatmentforcancer inchildhood:detectionbyanti-Müllerianhormone,inhibinBand ovarianultrasound.HumanReproduction2003;18:2368–74. [101]vanBeekRD,vandenHeuvel-EibrinkMM,LavenJS.Anti-mullerian

hormoneisasensitiveserummarkerforgonadalfunctioninwomen treatedforHodgkin’slymphomaduringchildhood.JournalofClinical EndocrinologyandMetabolism2007;92:3869–74.

[102]Lie Fong S,LavenJS, Hakvoort-Cammel FG, etal.Assessment ofovarianreservein adultchildhoodcancersurvivorsusing anti-Müllerianhormone.HumanReproduction2009;24:982–90. [103]LutchmanSinghK,MuttukrishnaS,SteinRC,etal.Predictorsof

ovarianreserveinyoungwomenwithbreastcancer.BritishJournal ofCancer2007;96:1808–16.

[104]RosendahlM,AndersenCY,LaCourFreieslebenN,JuulA,LøsslK, AndersenAN.Dynamicsandmechanismsofchemotherapy-induced ovarian folliculardepletioninwomenoffertileage.Fertilityand Sterility2010;94:156–66.

[105]Anders C, Marcom PK, Peterson B, et al. A pilot study of predictive markers of chemotherapy-related amenorrhea among premenopausalwomenwithearlystagebreastcancer.Cancer Inves-tigation2008;26:286–95.

[106]SuHI,SammelMD,GreenJ,etal.Antimullerianhormoneandinhibin Barehormonemeasuresofovarianfunctioninlatereproductive-aged breastcancersurvivors.Cancer2010;116:592–9.

[107]ClemonsM,SimmonsC.Identifyingmenopauseinbreastcancer patients:considerationsandimplications.BreastCancerResearchand Treatment2007;104:115–20.

[108]AmirE,SerugaB,FreedmanOC,ClemonsM.Endocrinetherapyfor breastcancer:prolongedamenorrhoeaisnotnecessarilyindicativeof menopause.BritishMedicalJournal2009;339:b4261.

[109]WangS,ParisF,SultanCS,etal.Recombinantcellultrasensitive bioassayformeasurementofestrogensinpostmenopausalwomen. JournalofClinicalEndocrinologyandMetabolism2005;90:1407–13. [110]RossiE,MorabitoA,DiRellaF,etal.Endocrineeffectsof adju-vant letrozole compared with tamoxifen in hormone-responsive

postmenopausalpatientswithearlybreastcancer:theHOBOEtrial. JournalofClinicalOncology2009;27:3192–7.

[111]JohannessenDC,EnganT,DiSalleE,etal.Endocrineand clini-caleffectsofexemestane(PNU155971),anovelsteroidalaromatase inhibitor,inpostmenopausalbreastcancerpatients:aphaseIstudy. ClinicalCancerResearch1997;3:1101–8.

[112]YuB,DouglasN,FerinMJ,etal.Changesinmarkersofovarian reserveandendocrinefunctioninyoungwomenwithbreastcancer undergoingadjuvantchemotherapy.Cancer2010;116:2099–105. [113]AndersonRA,CameronDA.Pretreamentserumanti-mullerian

hor-mone predicts long-term ovarian function and bone mass after chemotherapyforearlybreastcancer.JournalofClinical Endocrinol-ogyandMetabolism2011;96:1336–43.

[114]TorinoF,Barnabei A,DeVecchis L,AppetecchiaM,StrigariL, CorselloSM.Recognizingmenopauseinwomenwithamenorrhea inducedbycytotoxicchemotherapyforendocrine-responsiveearly breastcancer.EndocrineRelatedCancer2012;19:21–33.

[115]GeislerJ,EkseD,HelleH,DuongNK,LønningPE.Anoptimised, highlysensitive radioimmunoassayforthesimultaneous measure-mentofestrone,estradiolandestronesulfateintheultra-lowrangein humanplasmasamples.JournalofSteroidBiochemistryand Molec-ularBiology2008;109:90–5.

[116]LeeSJ,SchoverLR,PartridgeAH,etal.AmericanSocietyof Clin-icalOncologyrecommendationsonfertilitypreservationincancer patients.JournalofClinicalOncology2006;24:2917–31.

[121]ChangTK,WeberGF,CrespiCL,WaxmanDJ.Differentialactivation ofcyclophosphamideandifosphamidebycytochromesP-4502Band 3Ainhumanlivermicrosomes.CancerResearch1993;53:5629–37. [122]Tsai-TurtonM,LuongBT,TanY,LudererU.

Cyclophosphamide-induced apoptosis in COV434 human granulosa cells involves oxidativestressandglutathionedepletion.Toxicological Sciences 2007;98:216–30.

[123]MarcelloMF, Nuciforo G,RomeoR, etal.Structuraland ultra-structuralstudyoftheovaryinchildhoodleukemiaaftersuccessful treatment.Cancer1990;66:2099–104.

[124]MeirowD,DorJ,KaufmanB,etal.Corticalfibrosisandblood-vessels damageinhumanovariesexposedtochemotherapy.Potential mech-anismsofovarianinjury.HumanReproduction2007;22:1626–33. [125]Devine PJ, Perreault SD, Luderer U. Roles of reactive oxygen

speciesandantioxidantsinovariantoxicity.BiologyofReproduction 2012;86:27.

[126]HigdonRE, Marchetti F,Mahies JB,PhilipsGL. Theeffectsof cisplatinonmurinemetaphaseIIoocytes. GynecologicOncology 1992;147:348–52.

[127]Yeh J, Kim BS, Pereseie J, Page C. Declines in levels of hyperpolarization-activatedcation(HCN)channelsintheratovary aftercisplatinexposure.ReproductiveSciences2009;16:986–94. [128]YehJ,KimBS,LiangYJ,PeresieJ.Baselineandstimulatedserum

inhibinlevels asbiomarkersofcisplatin-induced ovarian damage in female rats. American Journal of Obstetrics and Gynecology 2008;198:e1–6.

[129]GonfloniS,DiTellaI,CaldarolaS,etal.Inhibitionofthe c-Abl-TAp63pathwayprotectsmouseoocytesfromchemotherapy-induced death.NatureMedicine2009;15:1179–85.

[130]Perez GI, Knudson CM, Leykin L, Korsmeyer SJ, Tilly JL. Apoptosis-associated signaling pathways are required for chemotherapy-mediated female germ cell destruction. Nature Medicine1997;3:1228–32.

[131]PerezGI,TaoXJ,TillyJL.Fragmentationanddeath(a.k.a.apoptosis) ofovulatedoocytes.MolecularHumanReproduction1999;5:414–20. [132]TakaiY,MatikainenT,JurisicovaA,etal.Caspase-12compensates forlackofcaspase-2andcaspase-3infemalegermcells.Apoptosis 2007;12:791–800.

[133]TingAY,PetroffBK.Tamoxifendecreasesovarianfollicularlossfrom experimentaltoxicantDMBAandchemotherapyagents cyclophos-phamideanddoxorubicinintherat.JournalofAssistedReproduction andGenetics2010;27:591–7.