ContentslistsavailableatScienceDirect
Critical
Reviews
in
Oncology/Hematology
j ourna l h o m e pa g e : w w w . e l s e v i e r . c o m / l o c a t e / c r i t r e v o n c
Multimodal
treatment
of
resectable
pancreatic
ductal
adenocarcinoma
Nicola
Silvestris
a,∗,1,
Oronzo
Brunetti
a,1,
Enrico
Vasile
b,
Francesco
Cellini
c,
Ivana
Cataldo
d,
Valeria
Pusceddu
e,
Monica
Cattaneo
f,
Stefano
Partelli
g,
Mario
Scartozzi
e,
Giuseppe
Aprile
f,h,
Andrea
Casadei
Gardini
i,
Alessio
Giuseppe
Morganti
j,
Vincenzo
Valentini
c,
Aldo
Scarpa
d,
Massimo
Falconi
g,
Angela
Calabrese
k,
Vito
Lorusso
a,
Michele
Reni
l,
Stefano
Cascinu
maMedicalOncologyUnit,CancerInstitute“GiovanniPaoloII”,Bari,Italy bDepartmentofOncology,AziendaOspedaliero-UniversitariaPisana,Pisa,Italy
cRadiationOncologyDepartment,GemelliART,UniversitàCattolicadelSacroCuore,Roma,Italy dARC-NETResearchCentre,UniversityofVerona,Verona,Italy
eMedicalOncologyUnit,UniversityofCagliari,Cagliari,Italy
fDepartmentofMedicalOncology,UniversityandGeneralHospital,Udine,Italy
gPancreaticSurgeryUnit,PancreasTranslationalandClinicalResearchCentre,SanRaffaeleScientificInstitute,‘Vita-Salute’University,Milan,Italy hDepartmentofMedicalOncology,GeneralHospitalofVicenza,Vicenza,Italy
iMedicalOncologyUnit,IRCCS,Meldola,Italy
jRadiationOncologyCenter,Dept.ofExperimental,DiagnosticandSpecialtyMedicine–DIMES,UniversityofBologna,Italy kRadiologyUnit,CancerInstitute“GiovanniPaoloII”,Bari,Italy
lMedicalOncologyDepartment,IRCCSSanRaffaeleScientificInstitute,Milan,Italy mModenaCancerCenter,PoliclinicodiModenaUniversitàdiModenaeReggioEmilia,Italy
Contents
1. Introduction...153
2. Morphologicalandclinical/biologicalcriteriaofresectability...153
3. Histologicalfeaturesandmolecularmarkers...154
4. Adjuvantchemotherapy...156
4.1. Historicalchemotherapyregimens...156
4.2. Newcombinationchemotherapyintheadjuvantsetting:mayintensificationrepresentastepforward? ... 156
4.3. Adjuvantchemotherapy:ongoingtrials...157
5. AdjuvantCRT...157
5.1. AdjuvantCRTcomparedtoobservationalone...157
5.2. AdjuvantCRTcomparedtochemotherapyaloneorobservation...158
6. Adjuvanttargettherapy...158
6.1. Moleculartargetagents...158
6.2. Immunotherapy...159
7. NeoadjuvanttherapyinresectablePDAC...160
8. Conclusions...161
Authorcontributions...161
Conflictofinterest...161
Fundings...161
References...161
∗ Correspondingauthorat:MedicalOncologyUnit,CancerInstitute“GiovanniPaoloII”,VialeOrazioFlacco,65,70124Bari,Italy.
E-mailaddresses:n.silvestris@oncologico.bari.it(N.Silvestris),dr.oronzo.brunetti@tiscali.it(O.Brunetti),e.vasile@ao.pisa.toscana.it(E.Vasile),
francesco.cellini@uniroma3.it(F.Cellini),cataldo.ivana@gmail.com(I.Cataldo),oncologiamedica2reparto@gmail.com(V.Pusceddu),aprile83@gmail.com(M.Cattaneo),
partelli.stefano@hsr.it(S.Partelli),marioscartozzi@gmail.com(M.Scartozzi),aprile.giuseppe@aoud.sanita.fvg.it(G.Aprile),casadeigardini@gmail.com(A.CasadeiGardini),
alessio.morganti2@unibo.it(A.G.Morganti),vincenzo.valentini@unicatt.it(V.Valentini),aldo.scarpa@univr.it(A.Scarpa),falconi.massimo@hsr.it(M.Falconi),
acalabrese22@gmail.com(A.Calabrese),vito.lorusso@oncologico.bari.it(V.Lorusso),reni.michele@hsr.it(M.Reni),cascinu@yahoo.com(S.Cascinu).
1 Theseauthorsequallycontributedintheelaborationofthemanuscript. http://dx.doi.org/10.1016/j.critrevonc.2017.01.015
a
r
t
i
c
l
e
i
n
f
o
Articlehistory: Received30August2016
Receivedinrevisedform11January2017 Accepted24January2017
Keywords:
Pancreaticductaladenocarcinoma Adjuvant
Chemotherapy Radiotherapy Targettherapy
a
b
s
t
r
a
c
t
Afteratimingpreoperativestaging,treatmentofresectablepancreaticadenocarcinoma(PDAC)includes surgeryandadjuvanttherapies,theformerrepresentingtheinitialtherapeuticoptionandthelatter aimingtoreducetheincidenceofbothdistantmetastases(chemotherapy)andlocoregionalfailures (chemoradiotherapy).Herein,weprovideacriticaloverviewontheroleofmultimodaltreatmentinPDAC andonnewopportunitiesrelatedtocurrentmoreactivepoli-chemotherapyregimens,targetedtherapies, andthemorerecentimmunotherapyapproaches.Moreover,ananalysisofpathologicalmarkersand clinicalfeaturesabletohelpcliniciansintheselectionofthebesttherapeuticstrategywillbediscussed. Lastly,theroleofneoadjuvanttreatmentofinitiallyresectablediseasewillbeconsideredmostlyin patientswhosemalignancyshowsmorphologicalbutnotclinicalorbiologicalcriteriaofresectability. Dependingontheresultsoftheseinvestigationalstudies,todayamultidisciplinaryapproachcanoffer thebestaddresstherapyforthesepatients.
©2017ElsevierB.V.Allrightsreserved.
1. Introduction
Pancreaticductaladenocarcinoma(PDAC)isthefourthleading causeofcancerdeathinEuropeandUnitedStateswitha5-year overallsurvival(OS)ratearound7%(Siegeletal.,2015).Resectable diseasecomprisesonly15–20%ofpatientsatdiagnosisandmanyof themarefoundtohavemicroscopicallypositivemarginsatthetime ofsurgery.Evenaftercurativesurgery,mostpatientswillrecurwith 5-yearsurvivalratearound10%,withlocoregionalandsystemic recurrenceratesfrom50%to80%andgreaterthan70%,respectively (Kamisawaetal.,2016).
Adjuvant treatments include systemic therapy that aims to reducetheincidenceofdistantmetastasesandchemoradiotherapy (CRT)potentiallyabletodecreasetheriskoflocoregionalfailure. Whiletheroleoftheformeriswellestablishedaccordingtothe resultsofrandomizedclinicaltrials,theusefulnessofthelatter remainscontroversial(OyasijiandMa,2015).Evaluationbya mul-tidisciplinaryteamofeachpatientshouldbemandatory(Pawlik etal.,2008).
Herein,we providea critical overviewontherole of multi-modal treatmentin PDACand onnewopportunities relatedto currentmoreactivepoli-chemotherapyregimens,targeted ther-apies,andthemorerecentimmunotherapyapproaches.Moreover, ananalysisofpathologicalmarkersand clinicalfeatures ableto helpcliniciansintheselectionofthebesttherapeuticstrategywill bediscussed.Lastly,theroleofneoadjuvanttreatmentofinitially resectable diseasewillbe consideredmostly in patientswhose malignancyshowsmorphologicalbutnotclinicalorbiological cri-teriaofresectability(Russoetal.,2016).
2. Morphologicalandclinical/biologicalcriteriaof resectability
Aftera preoperative staging (Silvestris et al., 2016)surgical resectionistheinitialtherapeuticoptionofpatientswithresectable PDAC(Barugolaet al.,2013; Serranoetal.,2015).Surgical indi-cationismainlyinfluencedbytheinvolvementofvesselsbutthe underpinningdiseasebiologyaswellasthegeneralpatients’ con-ditionsshouldalsobeconsidered.Vessel involvementis oneof themostimportantfeaturesthat needstobecarefullyassessed intheinitialevaluationofresectability.Regardingtumors involv-ingthepancreatichead,thereisageneralagreementinexcluding fromimmediatesurgerypatientswithPDACinvadingthesuperior mesentericartery.Themainlimitationsofpancreatectomywith arterialresectionarerepresentedbyapoorshort-andlong-term outcomeandtheabsenceofprospectivestudiesaimedtoclarify apossiblesurvival benefitin highlyselectedpatients(Mollberg etal., 2011).The MDAndersonCancerCenter proposeda
clas-sification of PDACresectability based onvesselinvolvement in whichlesionsmarginallyinvadingthesuperiormesentericartery aredefinedasborderlineresectablepancreaticcarcinoma(BRPC) (Katz et al., 2011,2013). The same classification identifies the superiormesenteric/portalveingradeofinvasionasanotherkey elementfordistinguishingresectabletumorsfromborderlineand locallyadvancedforms.Theroleofsuperiormesenteric/portalvein resectioninpatientswithPDACisstilla matterofdebate. Sev-eral meta-analyses reported conflicting results on the possible advantagesintermsofsurvivalinpatientswhounderwent pancre-atectomywithveinresection(SiriwardanaandSiriwardena,2006; Yuet al.,2014;Giovinazzoetal.,2016).Arecentmeta-analysis focusingonthisissuereviewed27studiesshowingincreased post-operativemortality,higherratesofnon-radicalsurgeryandshorter survivalafterpancreaticresectionwithsuperiormesenteric/portal veinresection(Giovinazzoetal.,2016).
AdistinctionhastobemadebetweenPDACinvolvingthehead ofthepancreasandtumorslocalizedinthepancreaticbody/tail due to the high rate of splenic vessels infiltration in the lat-tergroup.Severalreportsanalyzedtheimpactthattheinvasion ofsplenic vesselshasamong patientswithdistalPDAC(Partelli etal.,2011;Kandaetal.,2010).Inparticular,theinvasionofthe splenic artery, contraryto that of thesplenic vein, is a crucial prognostic factor of PDAC localized in the body and tail. Vas-cularinvolvement is not theonlycriterion that couldpreclude immediate surgery. In the absence of clearmetastatic disease, theoccurrenceofdistanttumorlocalizationshouldbesuspected when Ca 19.9, the only biomarker with demonstrated clinical usefulness for PDAC,is significantly elevatedin the absenceof obstructivejaundice (Goonetilleke and Siriwardena,2007). Fer-roneetal.demonstratedaclosecorrelationbetweentheCa19.9 valueandsurvivalafterpancreaticresection(Ferroneetal.,2006).A valueofpreoperativeCa19.9>200U/mLinpatientswithresectable PDAChasbeenproposedtoidentifypatientswithdiseasethatis notsuitableforup-frontsurgeryincombinationwithdurationof symptomsand pathological grading(Barugola et al.,2009).The performancestatusofpatientsisanotherimportantvariabletobe considered(Boecketal.,2007).Intriguingly,timeintervalbetween preoperative imagestaging and surgery correlatewiththe rate of unanticipated metastasis(UM)observedat operation. It was demonstratedthatthefrequencyofUMfor3shortertime inter-valgroups (0–6,7–13,and 14–20days)was12%.Thelongest3 groups(35–41,42–48,and49–86days)showedsimilar frequen-ciesofUMof35%,29%,and30%,withalinearrelationship(Glant etal.,2011).Sofar,Authorsrecommendanimagingnolongerthan 2–3weeksoldbythedateofsurgery,inallnewdiagnosedPDAC patients.
Insummary,anappropriatesurgicalindicationforPDAChas totakeintoaccountseveralfactorsthatincludetechnicalaspects (vascularinvolvement assessment) as wellasclinical/biological features.
3. Histologicalfeaturesandmolecularmarkers
ThemostimportantprognosticfactorforresectedPDACsisthe staging,accordingtoTNM7thedition(Bosman,2010;Edge,2010). Severalstudiesreportedthatsmallertumorsachievedabetter sur-vivalhaveabettersurvival (Phoaetal.,2005;Yamaguchietal., 1999).Currently,tumorsizedefines onlyearliercategories ofT (pT1<2cm;pT2≥2cm),ontheotherhand,involvementof peri-pancreaticsofttissuesandextrapancreaticstructuresidentifya moreadvancedstageofdisease(T3andT4respectively).Arecent prospectivestudyon757consecutiveresectedPDACpatients,has investigatedtheprognosticvalueofarevisedT-stageprotocol:pT1 as≤2cm,T2as2–4cmandpT3as>4cm;T4wasexcludedfromthe evaluationbecauseitusuallyreferstoBRPCornon-resectablePDAC (Sakaetal.,2016).TheAuthorsdemonstrated,throughunivariate andmultivariateanalyses,aclearassociationbetweenhigher T-stageandshortersurvivalalsoinnodenegativecasesandproposed toadopt thisnovelT-staging systemgiven itslinearprognostic value.
Assuming the established prognostic value of staging, sev-eralotherhistopathologicalfactorshave beenshowntoexerta potentialprognosticroleinresectedPDAC,althoughverylimited consensusexistsontheirevaluationandreportingamongmajor internationalguidelines(Takaorietal.,2016).
Theimportanceofnegativeresectionmargins(R0,i.e.minimum distancebetweentheneoplasmandtheedgeofthemargin>1mm) hasbeenlargelystressed,althoughdifferentopinionsonwhat con-stitutea resectionmargin and onthedefinitionof microscopic margininvolvementstill exists(Bockhornetal.,2014;Jamieson etal.,2013).Importantly,R0-resectionissignificantlyassociated withbetterprognosis,althoughitisachievedinonly36%ofpatients (Hartwigetal.,2011).ReliabilityoftheRclassificationdependson thethoroughness oftheclinicaland histopathological examina-tions(Wittekindetal.,2009),sothestandardizationofreporting mayhelpindefiningtheprognosticimpactofasubstantialcut-off formargin(Rauetal.,2012;Verbekaetal.,2006).Morerecently,a comprehensivearchivalanalysisevaluatingallthesurgical resec-tionmargins(SRM)wasperformedtodeterminetheeffectofR0 vsR1resectiononlocoregionalrecurrence,onsurvivalandonthe impactof adjuvant therapy (Osipov et al.,2016).The posterior resectionmarginresultedthemostclinicallysignificant. Further-more, a resectionmargin >2mm wasa significantpredictor of OSinpatientswhounderwentadjuvantchemotherapy(HR0.31, p=0.03)andCRT(HR0.40,p=0.19).
InresectedPDAC,thepresenceoflymphnodesmetastasisisalso anindependentprognosticfactorandastrongpredictorofoutcome atmultivariateanalyses(Schnelldorferetal.,2008;Shimadaetal., 2006;Valsangkaretal.,2013).Aminimumof12–17lymphnodesis recommendedtoavoidunder-staging(Huebneretal.,2012). Fur-thermore,forpatientswithN1disease,thelymphnoderatio(i.e. positivenodes/totalnodesexamined)appearstoberelatedto prog-nosis(Opfermannetal.,2014;Pawlik etal.,2007)anditseems tobeastrongerprognosticindicatorthanthenumberofpositive lymphnodesalone(Pawliketal.,2007).Tworecentstudieshave alsodemonstratedthatmetastasisinpara-aorticnodesarean indi-catorofpoorprognosis,regardlessofregionalnodalstatus(Komo etal.,2016;Paiellaetal.,2016).Neoplasticextra-nodalextensionis acommoneventinupto60%ofPDAC.Ameta-analysishas demon-strateditsstatisticallysignificantimpactonbothOSanddisease freesurvival(DFS),suggestingthatextra-nodalinvolvementshould
beincludedinthepathologicalreport(Luchinietal.,2016). Perineu-ralandvascularinvasionalongwithlowgradestromaldesmoplasia andthepresenceofaspecificsubsetofmacrophageinfiltrationare alsostronglyassociatedwithworseprognosis(Garceaetal.,2007; Wangetal.,2016;Huetal.,2016).
In recent years, several predictors of relapse have been addressedinPDACatmolecularlevel(Table1).KRASisthemain driverofPDACcancerogenesisand,asalreadyestablishedforother cancer types (Silvestris et al., 2014; Izar et al., 2014), distinct codon-mutationsmayhaveadifferentimpactonprognosis. Fur-thermore,KRASG12Vmutationmayberelatedtopoorprognosis inT3-resectedPDAC(Huangetal.,2015).Otherfrequentgenetic alterations,associatedwithanenhancedmalignantbehavior,occur inPDACexpressingTP53,CDKN2AandSMAD4associatedto over-expressionofCyclinD1 (Georgiadou etal.,2014;Oshimaetal., 2013).However,the realprognosticimpact of molecular alter-ationsinPDACisdebated.Atissuemicroarraystudyincluding127 patientswithresectedPDACdidnotconfirmacorrelationbetween SMAD4lossofexpressionandrecurrencepattern(Winteretal., 2013).Furthermore,anotherrecentanalysisfailedtodemonstrate significantdifferences in themutational profiles of KRAS,TP53, SMAD4,andCDKN2AamongPDACgroupswithdifferentmedian survivals. Thisstudy confirmedthat younger age,earlier stage, well/moderategradeofdifferentiationandnegativeresection mar-ginsarethemainprognosticfactorsdefiningtheverylongsurvivor groupofpatients(DalMolinetal.,2015).Thelackofastandardized histopathologicalreportandmolecularanalyticalprotocolsalong withtheneedsoffurtherinsightintothePDACcancerogenesis,may explainthesecontrastingresults.Othermolecularmarkershave beendescribedtoplayaroleasprognosticbiomarkersinPDAC. HighRab27A,aRASrelatedprotein,andp53expressionresulted correlatedwithpoorOS;Rab27Aexpressioncanbeconsideredan independentprognosticmarkerandapromisingnoveltherapeutic targetforPDAC(Wangetal.,2015).Elevatedtranscriptlevelsof MDM2P1promoterandlowp53mRNAexpression,significantly correlatewithworseprognosis(Grocholaetal.,2011).
Single-nucleotide polymorphisms of MAPK8IP1 and SOCS3, involvedintheNF-Binflammatorypathway,wereexaminedin 1308PDACpatientsandresultedassociatedwitha10–6-months survivaladvantagecomparedtonon-carriersintheresectedgroup (Reid-Lombardoetal.,2013).Polymorphismsinangiogenesisgenes suchasVEGFR-2,CXCR-2andPAR-1,mayexertapotentialimpact onPDACpatients’outcome(Uzunogluetal.,2013).Inanycase,in spiteoftheprogressachievedinthecomprehensionofangiogenic geneexpressioninPDAC,antiangiogenictargettherapyremainsa promise(Longoetal.,2016).
Patientsexpressingthematricellularglycoproteinsecreted pro-teinacidicandrichincysteine(SPARC)incancerstromalfibroblasts showed a significantly worse outcome than patients negative for SPARC in the stromal compartment (Infante et al., 2007). Other Authors reported that stromal expression of lumican, a smallleucine-rich-repeatproteoglycan,resultedstrongly associ-atedwiththereductionofmetachronousmetastasesandbetterOS comparedtostromallumican-negativePDACpatients.Itseffectcan bemostlikelyrelatedtoAktinhibition(Lietal.,2014).
Recently, the prognostic and predictive value of micro-RNA (miRNA)expressionprofilehasbeenwidelyinvestigatedin sev-eral cancers. A recent analysis on 538PDAC samples and 206 non-cancerous controls demonstrated that high expression of miRNA-21andmiRNA-31andlowexpressionofmiRNA-375are associatedwithpoorOSfollowingresection(Maetal.,2013). How-ever,theconsideration ofmiRNAsas diagnosticandprognostic biomarkers and as potential targetsfor therapy would suggest futurestudiesandstrongerprospectivevalidations(Brunettietal., 2015).Othergeneexpressionprofilestudiesindicateda36-gene
Table1
MainmolecularmarkersandtheirbiologicalsignificanceinPDAC.
Marker Typeofalteration Role Significance Refs.
KRAS G12Vcodonmutation Prognostic Poorprognosticindicatorin
T3-resectedPDAC
Huangetal.(2015)
TP53,SMAD4,CDKN2A Mutations Prognostic Poorprognosticindicators Georgiadouetal.(2014);
Oshimaetal.(2013)
CyclinD1 Overexpression Prognostic Poorprognosticindicator Georgiadouetal.(2014)
Rab27A Overexpression Prognostic Poorprognosticindicator/potential therapeutictargetforAkt-inhibitors
Wangetal.(2015) Lumican Stromalexpression Prognostic Bettersurvival Lietal.(2014)
MAPK8IP1andSOCS3 SNPs Prognostic Bettersurvival Reid-Lombardoetal.(2014) MDM2P1promoter Elevatedtranscriptlevel Prognostic Poorprognosticindicator Grocholaetal.(2011)
SPARC Cancerfibroblastexpression Prognostic Poorprognosticindicator Infanteetal.(2007)
miR-21,miR-31 miR-375
Highexpression Lowexpression
Prognostic Poorprognosticindicators (nodefinitiveresults)
Maetal.(2013)
CIP2A Highexpression Prognostic Poorprognosticindicator
(itsinhibitioninducesensitizationto gemcitabinetreatment)
Xuetal.(2016)
SIRT3andSIRT7 Lowexpression Prognostic Poorprognosticindicators (lowSIRT3levelarepredictiveof betterresponsetochemotherapy)
McGlynnetal.(2015)
hENT1 Expression Prognosticand predictive
Responsetogemcitabinetreatmentin nonmetastaticPDACs
Greenhalfetal.(2014);Poplin etal.(2013)
36-genesignature Differentexpressionprofiles Prognostic Independentprognosticpredictor Haideretal.(2014)
DNAmaintenanceand repairgenes
Defectivefunction Predictive Highrateofresponseto platinum-basedtherapy
Waddelletal.(2015)
4molecularsubtypes Specificpatternof
chromosomalalterationsand recurrentmutations
Prognosticand predictive
Prognosticstratificationaccordingto specificsubtypeandidentificationof potentialnoveltherapeutictargets
Baileyetal.(2016)
hHENT1:humanequilibrativenucleosidetransporter1;miR:miRNA;SPARC:secretedproteinacidicandrichincysteine;SNPs:Singlenucleotidepolymorphisms.
signatureasanindependentprognosticfactorofclinicaloutcome inPDAC(Haideretal.,2014).
Chemoresistance to gemcitabine can be restored via p53-reactivatingmolecules(CP-31398andRITA)inp53mutantsPDAC cell lines (Fiorini et al., 2015) as well as down-regulation of urokinase plasminogen activator (Khanna et al., 2011).Similar sensitizationtogemcitabinetreatmentcanbeinducedby down-regulationofcancerousinhibitorofproteinphosphatase2A(CIP2A) expression,whichconverselyactsasanindependentpoor prognos-ticindicatorinPDAC(Xuetal.,2016).Moreover,SIRT3andSIRT7, belongingtothebroadlyconservedsirtuingenefamily,havetumor suppressorpropertiesandSIRT3canalsobeconsideredapotential novelpredictivebiomarker(McGlynnetal.,2015).
Theexpressionofhumanequilibrativenucleosidetransporter 1 (hENT1) that permits the bidirectional passage into cells of pyrimidinenucleosidessuchasgemcitabine,capecitabine,and5FU (Spratlinetal.,2004;Yaoetal.,2011)isanimportantprognostic andpredictivebiomarkerforgemcitabineefficacyinpatientswith resectedPDAC(Greenhalfetal.,2014)butnotinmetastaticsubsets (Poplinetal.,2013).Itsuseinclinicalpracticeislimitedbythelack oflargeprospectivevalidationstudies(Viterboetal.,2016).
A retrospective study on 77 resected PDAC patients who underwentperioperative/adjuvantCRT(Rodriguez-Pascualetal., 2016)demonstratedthatExcissionRepairCross-Complementing 1(ERCC-1)immunohistochemicalexpressiondidnotpredictboth overallrelapsefreesurvival(RFS)andOSinchemotherapytreated patients.InCRTsubgroup,RFSwas15,6months(CI%9,8–21,2)and 3,8months(CI%2,4–5,3)forERCC-1negativeandERCC-1positive patients,respectively(p=0,0001),demonstratingthat radiother-apyimprovedRFSinERCC-1negativepatients.Authorspointedout theneedforprospectiverandomizedstudiestoconfirmtheERCC-1 expressionrole.
Finally,theadventofhighsequencingmethodsleadtothe iden-tification of 4molecularsubtypes in PDAC,each recognizedby specificpatternsofchromosomalalterationsandrecurrent muta-tionsindrivergenes.Thesecorrelatetodifferenthistopathological
characteristics,inferringdifferencesinthemolecularevolutionof PDACsubtypes and identifyingulterior chancesfor therapeutic development(Baileyetal.,2016).In particular,cases character-izedbyhighgenomicinstabilityusuallyexertinactivationofDNA maintenancegenes(BRCA1,BRCA2orPALB2)along withaDNA damagerepair deficiencymutationalsignature.Patientsbearing thesemolecularcharacteristics seem tobenefitfrom platinum-basedtherapywithhighrateofresponse(Waddelletal.,2015).
Recently, the presence of circulating tumor cells (CTCs) in peripheralbloodofPDACresectedpatientshasbeenproposedas anovelpoorprognosticfactor.Inparticular,thestudyperformed byPoruketal.demonstratedthepresenceofcytokeratin-positive CTCsandvimentin-positiveCTCsintheperipheralandportalblood samplesin78%and67%of50PDACpatients,respectively(Poruk etal.,2016).Apoorersurvivalratewasobservedonlyinthegroup ofpatientswithcytokeratin-positiveCTCs(p<0.01).Furthermore, thepresenceofcytokeratin-positiveCTCssignificantlycorrelated withabettersurvivalrateandwasasignificantindependent prog-nosticmarkeratmultivariableanalyses(p<0.01).Indeed,detection ofbothvimentinandcytocheratinpositiveCTCscorrelatedwiththe recurrencerate(p=0.01).
Theresultsofabovestudiesshowthatahugenumberof bio-logicalandmolecularmarkershavebeenreportedovertheyears aspotentialprognosticandpredictivefactors,openingnovel sce-nariosontherapeuticaloptionsinPDACs,althoughtheirpotential useinclinicalpracticewouldrequirelargerprospectivevalidation studies.Moreovertheadvanceinmolecularanalytical technolo-gieshasprovidedanindepthknowledgeofgenomicsalterations thatunderliePDACdevelopmentandprogression.Howeverafully standardized and widely sharedhistopathological report along withlargerprospectivevalidationstudiesofrobustbiomarkersare essentialconditionstodeeplyunderstandthebiologyofsuchan aggressivediseaseandbetteraddresstherapyandclinical man-agementinPDACpatients.
4. Adjuvantchemotherapy
Considering the high risk of recurrence even after radical surgery,theuseofadjuvanttherapieshaslargelybeenstudiedin resectedPDAC.Inparticular,differentrandomizedstudies eval-uated the role of postoperative chemotherapy alone for these patients.
4.1. Historicalchemotherapyregimens
Thefirstavailablerandomizedstudywasconductedabout30 yearsago.Sixty-onepatientswithPDAC(47patients)orampullary carcinoma(theremaining14patients)wererandomizedtoFAM (5-FU bolusplus doxorubicin plus mitomycin-C every 3 weeks for6 cycles) or observationalone(Bakkevold et al.,1993).The trialshowedanimprovementinOSwithchemotherapy(mOS:23 monthsvs11months,p=0.02;+11%inabsolute2-yearsurvival, from32%to43%)evenifthecurvesoverlappedafter2yearwith nodifferencesinlong-termsurvivalanda5-yearsurvivalratein thechemotherapygroupofonly4%.Thischemotherapyregimen wasassociatedwithconsistenttoxicity,with1toxicdeathover31 treatedpatients,andwithseverecardiotoxicityandnephrotoxicity reportedin2patients.Apartfromtoxicity,themajorlimitsofthis trialwerethesmallnumberofpatientsandtheinclusionofboth pancreaticandampullarymalignancies.
AlargerandmorecomplextrialwasconductedinEuropeinthe nextdecadebytheEuropeanStudyGroupforPancreaticCancer (ESPAC-1trial)(Neoptolemosetal.,2001).Thetrialhadafactorial designwithtworandomizations:thefirstforchemotherapyvsno chemotherapyandthesecondforCRTvsnoCRT.Atotalof285 patientswererandomizedintheoriginaldesignofthestudywhile additional188patientswererandomizedeitherfor chemother-apyorobservationaloneforatotalof473patients.Chemotherapy wasadministeredwithbolus5-FUat425mg/m2for5consecutive daysevery28daysfor6cycles,combinedtofolinicacid. Regard-ingtheroleofchemotherapy,theESPAC-1trialshowedanincrease inOSwithchemotherapyconsideringallenrolledpatients(mOS: 19.7monthsvs14.0months;p=0.0005)(Neoptolemosetal.,2001; Neoptolemosetal.,2004).Thesurvivalcurvesbegantoseparate after6monthsandremaineddistantevenafter5years,withan absolutesurvivalbenefitat2-and5-yearsof10%and13%, respec-tively.
Besides5-FU, alsogemcitabinewasinvestigatedasadjuvant chemotherapyforresectedPDAC.Thefirststudywasconducted between1998and2004inGermanyandAustriabytheCharite´ı Onkologie(CONKO)group(CONKO-001trial).Thisstudycompared weeklygemcitabine(atthedoseof1000mg/m2 atdays1,8,15 every28for6cycles)vsobservationalonein368patients(Oettle etal.,2007).Inthistrial,gemcitabineprolongedDFS(13.4months vs6.7 months,p<0.001) andOS (22.8 monthsvs20.2 months, p=0.01)withanabsoluteincreaseinsurvivalof10%at5years. Furthermorethesedatawereconfirmedwithalongerfollow-up (Oettleetal.,2013).EveniftheimprovementintermsofOSwere modestinthissubsetofpatients(only2.6months),theaggressive biologicalbehaviourofthismalignancyshouldbeconsidered.
Asecondstudyconductedon119Asiaticpatientswhoreceived gemcitabinefor only 3 months compared toobservation alone showed an improvement in terms of DSF (HR=0.60; CI95% 0.45–0.89;p=0.01)butnotforofOS(HR=0.77;CI95%0.51–1.14; p=0.19)(Uenoetal.,2009).Thelownumberofenrolledpatients influencedtheseresults.
Withtwo effectivedrugs available, gemcitabineand 5-FU, a comparisonbetweenthemwasperformedin2randomized tri-als.TheESPAC-3trialcomparedgemcitabineto5-FUinmorethan 1000resected patients.The studyinitiallyincludedathird arm withobservationalone that wasendedfollowing theresultsof
bothESPAC-1andCONKO-001trials(Neoptolemosetal.,2010).The studyshowedverysimilarresultsintermsofqualityoflife(QoL), DFS,andOSbetweenthetwoarmswithamOSofabout23months. Thetoxicityprofiledifferedbetweenthetwoarms: haematolog-icaltoxicitywashigherwithgemcitabinewhile gastrointestinal toxicitywashigherwith5-FU.
AretrospectiveanalysisfromtheESPAC-3trialrevealedthat completingall6monthsofplannedadjuvantchemotherapyis cru-cialinderivingbenefitswhilethetimeoftreatmentinitiation(<12 weeks)isnot(Valleetal.,2014).Apotentialbiasrelatedtothe tim-ingoftreatmentcouldberepresentedbytheinclusionofpatients whoexperiencedearlydeathoraprogressiondiseaseand, there-foredidnot completetheentireplannedchemotherapy.Sofar, even aftertheexclusionof patientswhodied within8months afterresection,OSandrecurrence-freesurvivaloftheremaining 889patientsresultedimproved.
TheRTOG 97-04trial comparedeither gemcitabineor 5-FU, beforeandafterCRT(Regineetal.,2011).Therewasnosignificant differenceintermsofmOS(p=0.51)withahigherrateoftoxicity inthegemcitabinearm(p<0.001).Abenefitcorrelatedwith gemc-itabinewasobservedinthemultivariateanalysisforpatientswith PDAClocalizedinthepancreatichead(p=0.08).
Arecentmeta-analysisevaluatedtherole ofadjuvant gemc-itabinein2017resectedPDACpatientsinfourphaseIIIrandomized trials (Yu et al., 2015). In particular, two of them compared gemcitabineto5-FU/folinicacidandtheothertwocompared gemc-itabinetobestsupportivecare(BSC).Thismeta-analysisconsidered an homogenous population of patients among these studies (Q=4.371;I=31.37%;p=0.224)andsuggestedthatadjuvant gem-citabineimprovedOScomparedtobothBSCor5-FU/folinicacid treatmentsinresectedPDACwithanoverallHRof0.88(p=0.014). S-1,anoralfluoropyrimidine,wascomparedtogemcitabineas adjuvant chemotherapyfor Asiaticresected PDACintwo phase IIItrials(Shimodaetal.,2015; Uesakaetal.,2016).Theformer (Shimodaetal.,2015)didnotdemonstrateasignificantdifference intermsofDSF(14.6vs10.5months;p=0.293)betweenpatients treatedwithS1(29patients)andgemcitabine(28patients).Onthe contrary,thesecondlargertrial(Uesakaetal.,2016)considering 385patientsshowedanimprovementof5yearOSbetweenS-1 andgemcitabine(44.1%vs24.4%).Thehypotheticaldifferencein pharmacologicalmetabolismofAsiaticpopulationcouldinfluence theapplicabilityoftheseresultsindifferentpopulations.
Today,singleagentchemotherapyboth withgemcitabineor 5-FUisconsideredasstandardadjuvantchemotherapyforPDAC (Table 2)in theguidelinesof severalWesterncountries(NCCN Guidelines,2016;AIOMGuidelines,2015;ASCOguidelines2016).
Similarlytosurgery,therelevanceofthecenterofcareinterms of outcome forresectable PDAC patientscandidateto adjuvant systemic treatmenthasbeen reported.A retrospectiveanalysis (Mandelson and Picozzi, 2016), considering 245 patients, 57% treatedathighvolumecenter(HVC)and43%treatedatcommunity oncologist(CC)showedanadvantageintermsofmOSand5-year OSrateforHVCcenterscomparedtoCCcenters(44monthsvs28 months,p>0.01;38.8%vs24.8%,p>0.01).Thesedatasuggestthat, aHVCshouldbepreferrednotonlyforsurgerybutalsoforadjuvant systemictreatments.
4.2. Newcombinationchemotherapyintheadjuvantsetting: mayintensificationrepresentastepforward?
Basedontheassumptionoftheearlydisseminationof pancre-aticcancercells,severalongoingclinicaltrialsareevaluating,inthe adjuvant setting,differentcombination chemotherapyregimens whichareefficaciousintheadvancedsetting(Garrido-Lagunaand Hidalgo,2015).
Table2
RandomizedphaseIIIstudiesofadjuvantchemotherapyversussurgeryalone.
pts Regimen mOS yearsOS 5-yearsOS Refs.
7572 5-FluorouracilObservation 21.614.2 NR NR 29 13 Neoptolemosetal.(2004)
179175 GemcitabineObservation 22.820.2 47.542 20.710.4 Oettleetal.(2007);Oettleetal.(2013)
5860 GemcitabineObservation 22.318.4 48.340 23.910.6 Uenoetal.(2009)
N.pts:numberofpatients;mOS:medianoverallsurvival;FAM:5-FUbolusplusdoxorubicinplusmitomycin-C.
PACT-7,anItalian phase IIrandomizedtrial,testedthe con-ceptofchemotherapyintensificationandallocated102radically resectedstageIB-IIIPDACpatientstostandardgemcitabineorPEFG (cisplatinandepirubicin40mg/m2,day1;gemcitabine600mg/m2, days1,8;5-FU200mg/m2 daily,days1–28)(Renietal.,2012). Althoughproducingmorehaematologicaltoxicities,the combina-tionregimenyieldedinterestingresultsintermsof mDFS(15.2 monthsvs11.2monthsinthegemcitabinearm),1-yearDFSrate (69.4%vs49%),andmOS(28.9monthsvs24.8months).
The combination of gemcitabine(1000mg/m2,day 1, 8 and 15)andcapecitabine(830mg/m2 twicedailyondays1–21every 28days)comparedtogemcitabinealonehasbeentestedin ESPAC-4,arandomizedphase IIIstudy(Neoptolemosetal.,2016).This trialconsideredradicallyresectedPDACorperiampullarycancer patients.PrimaryendpointwasOS;secondaryendpointswereOS rateat2and5years,toxicityandQoL(NCT00058201,2016).Early resultspresentedatthelastASCOmeetingregarding730patients showedthatmOSwas28monthsand25.5monthsfor combina-tionarmandgemcitabinealone,respectively(HR=0.82;p=0.032), withasimilartoxicityprofile.Theimmaturefollow-updoesnot allowtoconsiderthesedatasufficientlyreliable,asevidencedby thelargeoverlapoftheconfidenceintervalsofmOSs.Inaddition, dataof2-yearOSratearenotyetavailable.Itisalsounclearwhat theoverallpatientpopulationofthestudyis.Infact,amaximum limitofCa19.9wasnotconsideredasaninclusioncriterionfor theinclusionofpatientswithaCA19.9baselinevalueofover8000. Furthermore,8%ofpatientswerenodepositive.Lastlya postop-erativerestagingwasnotrequiredthustheinclusionofpatients withmetastaticdiseasecannotbeexcluded.Althoughpromising, thesedataarenotsufficientlymaturetoconsiderthiscombination regimenasanewtherapeuticstandard.
4.3. Adjuvantchemotherapy:ongoingtrials
APACT(ABI-007-PANC-003)isaglobal,open-label,randomized phaseIIIstudycomparingnab-paclitaxelplusgemcitabinevs gem-citabinealoneinover850patientswithradicallyresectedPDAC (Temperoetal.,2016).Thisstudyisbasedontheresultsofthe phaseIIIMPACTtrial,whichshowedasignificantoutcome advan-tageforthecombinationcompared togemcitabinealoneinthe advancedsetting(VonHoffetal.,2013).DFSwastheprimarytrial endpoint;secondaryendpointswereOSandsafety.Thetrialhas recentlycompleteditsaccrual,withtheenrollmentof866patients. FollowingtheresultsofPRODIGE4/ACCORD11,that demon-stratedthesuperiorityofFOLFIRINOXovergemcitabinealonein themetastaticsetting(Conroyetal.,2011),PRODIGE24/ACCORD 24wasdesigned asa phaseIII, multicenter,randomized, open-labeltrialtocomparemodifiedFOLFIRINOX(without5-FUbolus)to gemcitabinealoneafterdiseaseresection.Targetsamplesizewas 490patientswithECOGPS0-1andwithoutpriorradiotherapyand chemotherapy.Theprimarystudyendpointofthisongoing trial isDFSat3years,secondaryendpointsareOSanddiseasespecific survivalat3years.
GIP-2isanItalian,phaseIII,multicenter,open-label, random-izedphaseIIIstudycomparing6monthsofFOLFOXIRI(amodified tripletcontainingirinotecan,oxaliplatin,and5-FU)vsgemcitabine aloneinresectedPDAC.Thistrialisenrolling310patientswith
sur-gicallyresectedstageI–IIIPDAC,ECOGPS0-1andadequateorgan function.TheprimaryendpointisDFS;secondaryendpointsareOS, safetyandtolerability.
Following the results of PACT-7, the role of postoperative administrationofa4-drugcombinationisbeingtestedinanother randomizedItalian study.PACT-15is a phaseII–III multicenter, open-labeltrialincludingthreearms:(1)adjuvantPEXG(cisplatin, epirubicin,gemcitabine,andcapecitabine)perioperativePEXG,and adjuvantgemcitabine.
Thestudywasdesignedtoinclude370previouslyuntreated stageI–IIresectablePDACpatients.TheprimaryendpointisDFS at1year;secondaryendpointsareradiological,biochemical,and pathologicalresponserates(neoadjuvantarmonly),assessmentof lymphnodestatus,surgicalmortality,morbilityandresectionrates, andtreatmenttolerability.
AttheASCO2016meeting,theprojectofarandomizedphase IIstudy(Sohaletal.,2016)comparingpreoperativemFOLFIRINOX orgemcitabine/nab-paclitaxelcombination,followedbysurgical resectionand12weeksofidenticalpostoperativechemotherapy inresectablePDAC,waspresented.Primaryoutcomeis2-yearOS, withatotalsamplesizeof112patients.Theresultsofthisstudy willbeveryinterestingbecauseitisaheadtoheadcomparison betweenthetworegimensusedinclinicalpracticeinmetastatic PDAC.
5. AdjuvantCRT
CRTiswidelyusedintheadjuvantsettingeveniftheresults regarding its effectiveness remain controversial compared to chemotherapyalone.
5.1. AdjuvantCRTcomparedtoobservationalone
Thefirstrandomizedtrialinvestigatingthistopicwasperformed byGastrointestinalTumorStudyGroup(GITSG)on43patientswho underwenteitherCRTorobservationaloneafterR0radicalsurgery (KalserandEllenberg,1985).CRTconsistedof40Gyin6weekswith concurrentintermittentbolusof5-FUat500mg/m2ondays1–3 and29–31,followedbyfurther5-FUfor2years.Anunacceptably lowrateofaccrualcombinedwiththeobservationofincreasingly largesurvivaldifferencesbetweenthestudyarmswereresponsible foraprematureterminationofthestudy.AbenefitinmOSfavored CRTvsobservation(21monthsvs10.9months;p=0.03),aswell asforthe2-yearOS(42%vs15%;p=0.03).Basedontheseresults, adjuvantCRTbecameastandardpracticeintheUnitedStates.
EORTC40801trialaccrued218patientsoperatedfor pancre-aticorampullarytumor(Klinkenbijl etal.,1999).Amongthem, 114presented T3(orhigher)and/orN1 pancreaticmalignancy. Aftersurgery,patientswereallocatedtoobservationoradjuvant CRT.Thetherapeuticstrategyreproducedtheoneconsideredin theGITSGstudywiththeexceptionof2yearsoftherapywith5-FU afterCRT.Themainanalysisonthewholegroup(pancreaticand ampullarylesions)failed todetectanysignificantimprovement of OS or DFS. A subgroup analysis, which focused on pancre-atic tumors, reported a non-significant trend in favor of CRT. Therecurrencepatternswerenotsignificantlydifferentbetween the2groups,suggestingtheineffectivenessofCRT.The11-year
follow-upanalysisofthatstudyconfirmedtheinitiallypublished short-termfindings(Smeenketal.,2007).Somelarge retrospec-tiveanalysessuggestedapositiveinfluenceofCRTinthissubset of patients. Herman et al. compared 271 patientswho under-wentCRT(50Gyplus5-FU)topatientsnotreceivingCRT(Herman etal.,2008).CRTwasfoundtoimprovemOS(21.2monthsvs14.4 months;p<0.001).ArecentanalysisbytheUS-basedSurveillance, EpidemiologyandEndResultsprogramconsidering2532patients who underwent neitheradjuvant radiotherapy norobservation reportedaresultofmedianOSandDSFsignificantlyhigherinthe postoperativeradiotherapygroup(mOS:20monthsvs16months; DFS:22monthsvs18months;p<0.0001)(SugawaraandKunieda, 2014).Theconflictingresultsoftheabovestudiesleavetherole ofCRTunsolvedcomparedtoobservationaloneinthissubsetof patients.
5.2. AdjuvantCRTcomparedtochemotherapyaloneor observation
Thefirstlargestclinicalstudycomparingadjuvantconcurrent CRTtochemotherapyaloneorobservationwastheESPAC-1trial (Neoptolemos et al., 2004) thatramdomized 289patientswith resectedPDACtoreceiveCRTalone(20Gyoveratwo-weekperiod plus5-FU),5-FUalone,CRTandsequential5-FU,orobservation. MedianOSforadjuvantchemotherapyandconcurrentCRTwere 20.1 and 15.9months, respectively (p=0.009). One-year recur-rencerateforconcurrentCRTandchemotherapywas46%vs55%, associatedwithbothshorterrecurrencefreesurvival(10.7vs15.2 months,p=0.04)withrespecttoaworsetoxicityprofileforpatients treatedwithCRT.Inthistrial,adjuvantchemotherapyshoweda sig-nificantsurvivalbenefitcomparedtoadjuvantCRT,evenifthese resultscouldbeinfluencedbyboththesuboptimalscheduleofCRT adoptedandtheuseofnon-conformal2Dtreatmentplanning.
The EORTC-40013-22012/FFCD-9203/GERCOR phase II study randomized90PDACpatientswithin8weeksafterR0resection, toreceive4cyclesofgemcitabine(controlarm)orgemcitabinefor 2cyclesfollowedbyweeklygemcitabinewithconcurrentradiation (50.4Gy;CRTarm).MedianDFSwas12and11monthsintheCRT andcontrolarm,respectively,withamOSof24monthsinboth arms.Moreover,localrelapseratewas11%and24%forCRTand controlarm,respectively(VanLaethemetal.,2010).
Koobyetal.analyzeddatafrom11526patientsfromtheNational CancerDataBase(NCDB)(Koobyetal.,2013).Ofthese1029(8.9%) underwentchemotherapy,5292(45.9%)underwentCRT(excluding patientswhoreceivedradiotherapyastheonlyformofadjuvant therapy),and5205(45.2%)underwentobservationalone.CRTarm showed the best OS (HR: 0.70, CI95%: 0.61–0.80) in a propen-sityscoredmatched comparisonwithchemotherapy (HR: 1.04, CI95%:0.93–1.18)andobservation.Asimilaranalysiswasperformed byRutteretal(Rutteretal.,2015).TheseAuthorscollecteddata fromtheNCDBonR0/R1resectedpatients;6165patientsreceived chemotherapy(38%)orCRT(62%).Themediandoseofradiotherapy was50.4Gy.SubsetanalysesshowedthatCRTwasassociatedwith improvedOSamongpatientswithpT3orpN1diseaseand particu-larlyamongpatientswithR1resection.Itshouldbeobservedthat CRTwasassociatedwithanimprovementinOSwhenitwas admin-isteredafter1–3monthsofsystemicchemotherapy.Amulticenter retrospectivereview byMorgantietal.considered955patients withR0/R1resection(Morgantietal.,2014)treatedwitheitherCRT orCTalone.CRTwasadministeredwithdoses>45Gy(45–60, con-ventionalfractionation),and5-FUorgemcitabinewereadoptedas concurrentchemosensitizers.Five-yearOSwas41.2%vs24.8%with andwithoutadjuvantCRT,respectively.MedianOSafterCRTwas 39.9monthsvs27.8monthsafterchemotherapyalone(p<0.001). Thedifferenceinmediansurvivalbetweenpatientstreatedwith CRTwithorwithoutfurtheradjuvantchemotherapyandpatients
treatedwithadjuvantchemotherapyalonewasstatistically signif-icant(39.5monthsvs27.8months,p<0.001).Table3summarizes someofthementionedtrialscomparingadjuvantCRTto observa-tionaloneortochemotherapy.
Twometa-analyses(the first on5 randomized trials includ-ing939patients;thesecondon4randomizedtrialsincluding875 patients)didnotrevealanysignificantclinicalbenefitfromtheuse ofCRT,withasmallsurvivalbenefitfavoringtheadoptionof adju-vantCRTforpatientswhoreportedanR1resection(Stockenetal., 2005;Butturinietal.,2008).Renetal.conductedanother meta-analysison15randomizedtrialsonadjuvanttherapyandobserved that,comparedtoobservation,chemotherapyimprovedDFSand OSwhileCRTdidnot(Renetal.,2012).Similarly,Liaoetal. per-formedameta-analysison9randomizedtrials(3033patients)to directlycompareadjuvantCRTtochemotherapy(Liaoetal.,2013). TheydidnotfindanadvantageintheuseofCRTconcerningthe survivalratecomparedtotheuseofchemotherapywithrespect toanincreasedtoxicityprofile.Theseanalysesdonotprovidedata ontherateoflocalrecurrence,whichcouldbeanimportant end-pointforthesepatientsintermsofQoL.Furthermore,itshouldbe highlightedthatallthesemeta-analysesincludedtheGITSG,EORTC andESPAC-1trials,whichadministeredasuboptimalandobsolete scheduleofradiotherapy.
On thebasis of publishedtrialsand internationalguidelines (NCCNGuidelines,2016;AIOMGuidelines,2015,ASCOguidelines 2016),adjuvantCRTshouldbeproposedtoapatientwithresected PDACwhich presentsmicroscopicpositivemarginsand/or posi-tivenodepositivediseaseafter4–6monthsofsystemicadjuvant chemotherapy.Novelradiotherapicapproacheswhichattemptto shortencoursesandintensifyradiotherapywithtechniques includ-ingintensity-modulatedradiationtherapyandstereotacticbody radiationtherapymayrepresentanovelstrategytoimprove locore-gionalcontrolandtolerability(Bowengeetal.,2015;Ahnetal., 2016).Inthisscenario,thecurrentlyongoingAmericanRTOG0848 andEuropeanEORTC40084-22084willbetterdefinetheroleof modern3-dimensionalconformalradiationtherapy.
6. Adjuvanttargettherapy
PDACshows a peculiar biological complexity leading tothe evidence of several, potentially effective molecular targets for specificallydesignedtherapeuticoptions(Ahnet al.,2016).The tumortransformationprocessisinfactlinkedtotheacquisition of progressivesingle mutationsinducing genomic instabilityin severalcellular pathways, including KRAS, hedgehog, integrins, transforming growth factor  (TGF-), the Wnt/Notch signal-ing, but also molecular pathways activated by the TGF-, the hemophiliccelladhesionandinvasion,theregulationofG1/Scell cycletransition,EGFRaswellasDNAdamagecontrolandapoptosis (DiMarcoetal.,2016).Asaconsequence,adjuvanttargeted thera-piesinthissettingofpatientsmayrepresentaveryintriguingfield ofresearch(Table4).
6.1. Moleculartargetagents
Theroleofcetuximab,amAbanti-EGFR,inthepostresection treatmentofPDAChasbeeninvestigatedinamulticentrephase IIclinical trial (ATIPtrial) in which 76 resected patients, were enrolledtoreceivegemcitabineandcetuximabasadjuvanttherapy (Fenstereretal.,2013).Theprimaryaimwastodeterminewhether theexperimentalarmcouldleadtoanincreasedDFSwhen com-paredtothereportedresultsofgemcitabinealoneinthissetting. StudyfindingswerenegativewithamDFSof10monthsandaDFS rateof27.1%at18months.Theseresultswereinferiortothose reportedforgemcitabinealone.Therewasnopre-planned
strati-Table3
Studiescomparingadjuvantradiotherapytoobservationaloneortochemotherapy.
Design Arms RTschedule N.pts mOS(months) 5yyOS Refs.
RCT CRTvsObs 40Gy/20fx(Split
Course) 43 CRT:21 Obs:10.9 p=0.03 CRT:42% Obs:15% (2yyOS)
KalserandEllenberg (1985)
RCT CRTvsObs 40Gy/20fx(Split Course) 218 CRT:17.1 Obs:12.6 p=0.099 CRT:23% Obs:10% (pancreaticlesions only) Klinkenbijletal.(1999) RCT CRT±CTvs no-CRT±CT(i.e.: Obs,CTalone) 40Gy/20fx(Split Course) 289 CRT±CT:15.5 no-CRT±CT:16.1 p=0.24 CRT±CT:10% no-RTCT±CT:20% p=0.05 Neoptolemosetal. (2004)
Retrosp CRTvsObs 50Gy/28fx(Median Dose) 616 CRT:21.2 Obs:14.4 p<0.001 CRT:20.1% Obs.15.4% p<0.001 Hermanetal.(2008)
Retrosp CRTvsno-CRT(i.e.: Obs,CTalone) 45–60Gy/25–30fx 955 CRT:39.9 no-CRT:24.8 CTalone:27.8 p<0.001 CRT:41.2% no-CRT:24.8% p<0.001 Morgantietal.(2014)
RCT:randomizedcontrolledtrial;Retrosp:retrospectiveNo.:number;Pt:patients;mth:months;5yyOS:5yearsoverallsurvival;2yyOS:2yearsoverallsurvival;vs:Versus; Gy:Gray;fx:numberofdeliveredfractions;CRT:chemoradiotherapy;Obs:observation;no-CRT:noneCRTadministration;CT:Chemotherapy
Table4
Maintrialinadjuvantsettingwithtargettherapyandimmunotherapy.
Trial Phase Target Design Results Ref
TargetTherapy
CONKO–005 III EGFR-TKI GemvsGem-erlotinib DFS:11.6vs11.6months
OS:26.5vs24.6months
Sinnetal.(2015)
ATIPtrial II EGFR Gem–cetuximab inR0-R1PDAC
mDFS:10.0months DFSrateat18months:27.1%
Fenstereretal.(2013)
RTOG–0848 III EGFR–TKI Random1.Arm1:Gem;Arm2: Gem–erlotinib;
Random2.Arm3:CT–(Arm1or2); Arm4:CT(5FU)+concurrentRT
Arm2earlyclosed(2014)
ResultsawaitedforCRTvsCT(ongoing)
Lietal.(2014)
Immunotherapy
GI-4000 II Krasmutated-vaccine Gem-placebovs Gem-GI4000 1yearsurvival:56%vs72% 11.4weekadvantageinmOS Muscarellaetal.(2012) G-VAXpancreas vaccine II Irradiate,Transfected GM-CSFcells
GVAX+5FUbasedCRT mDFS:17.3months mOS:24.8months 1yearsurvival:85%
Lutzetal.(2011)
Algenpantucel–L vaccine
II Hyperacuterejection Gemand5FU
basedCT+algenpantucel-L 12monthsDFS:62% 12monthsOS:86% Hardacreetal.(2013) ClinicalTrials NCT01072981
III Hyperacuterejection Gemaloneorwith5FU-RT+/− algenpantucel-L
ongoing NCT01072981(2016)
CHT:chemotherapy;DFS:diseasefreesurvival;EGFR:epidermalgrowthfactorreceptor;Gem:gemcitabine;mDSF:mediandiseasefreesurvival;mOSmedianoverall survival;PDAC:pancreaticductaladenocarcinoma;RT:radiotherapy;TKItirosinkinaseinhibitor;5-FU:5-fluorouracil.
ficationofthepatientsbyKRASstatus,but69.1%ofpatientshad amutationinthecodon12or13oftheKRASoncogene.However, nodifferencesinDFSorOSwereobservedbetweenwildtypeor mutatedKRASpatients.Theseresultswerenotsurprising,dueto thelackofactivityofcetuximabinthemetastaticsetting.
The efficacy of EGFR-TKI erlotinib as adjuvant therapy in resectedPDAChasbeenevaluatedintwo majorphase III clini-calstudies:theCONKO-005andtheRTOG-0848trials.Theformer study was a phase III randomized trial designed to evaluate theefficacyoferlotinib (100mgp.o.daily)incombination with gemcitabineafterR0resection(Sinnetal.,2015).Fourhundred thirty-sixpatientswererandomizedwithin8weeksfrom resec-tiontogemcitabine–erlotinibvsgemcitabine.Stratificationfactors includedlymphnodesinvolvement,surgicaltechniqueandstudy centre.PrimaryendpointwasDFS,secondaryendpointincluded OSandsafety.Thestudyfailedtomeetitsprimaryendpointwith no differences between the two arms in DFS (11.6 months vs 11.6monthsinthegemcitabine-erlotinibandgemcitabinealone arms,respectively)norinOS(24.6monthsvs26.5months).The RTOG-0848wasarandomizedtrialthataimedtoevaluatewhether erlotinib and/or radiation could improve OS in resected PDAC patients(LiandO’Reilly,2015).Theoriginalstudywasdesigned
witha firststeprandomization intotwo arms:(1) gemcitabine alonefor5cyclesor(2)gemcitabine-erlotinibfor5cycles.Patients freefromtumorrecurrencewerethenrandomizedtoreceiveone additionalcycleofchemotherapy(basedonthefirst randomiza-tion–arm3)oronecycleofchemotherapyfollowedby5-FUbased CRT(arm4).Thisstudyaimedtoprovideabetterunderstanding oftheroleoferlotinibintheadjuvantsettingbutalsoattempted toanswerthequestionofthevalueofcombinedCRTtosystemic chemotherapyinradicallyresectedpatients.Basedonthe disap-pointingresultsfromLAP07phaseIIItrial(Hammeletal.,2013),the studywasamendedtocloseenrollmentintheerlotinibplus gem-citabinearminearly2014andiscurrentlyongoingtodetermine whethertheuseofconcurrentfluoropyrimidineandradiotherapy isabletoimprovesurvivalinresectedPDACpatients.
6.2. Immunotherapy
Afurtherareaofincreasinginterestforresearchintheadjuvant settingisimmunotherapy.Globally,PDAChasalwaysbeen con-sideredanon-immunogenicmalignancy.Thisisdueinpart,toits microenvironmentthatincludesinflammatorycells(mainly lym-phocytes,plasmacells,macrophagesandmastcells)which,rather
thanreactingagainstthetumor,seemtopromoteaninflammatory microenvironmentthathelpstumorcellstoescapefromimmune surveillanceviaparacrine cross-talkmechanism (Puzzoniet al., 2016).PDACissurroundedbyadesmoplasticstromawithinwhich neoplasticcellsareabletostimulatetheproliferationof fibrob-lasts,specificallypancreaticstellatecells(PSCs).PSCscontributeto theadditionalfibrosisformation,theypromotetumorprogression andtheyseemtofacilitateimmuneevasion,chemoresistanceand recurrenceofPDAC(Ansarietal.,2015).Ifontheonehandthis com-plextumormicroenvironmentmaymakeanimmunotherapeutic approachinthemetastaticoradvanceddiseasedifficult,onthe otherhanditcouldbeawinningstrategyintheadjuvantsetting. Onlypreliminarydataareavailableatthemomentandongoing tri-alswillhopefullyclarifytheefficacyofsuchatreatmentapproach inthenearfuture.
Morethan95%of PDACareassociated withKRAS oncogenic mutations,mostas asingle pointmutation atcodon12 result-inginaconstitutiveactivationofKRAS(Mohammedetal.,2015). Thismutationleadstoupregulation/dysregulationoftheEGFRand inductionofproliferationbyactivationofmitogenicpathway.The amino-acidsubstitutionatposition12oftheRASproteincanbe recognizedbothbyhelper T-cellsand cytotoxicT-cellsand can beusedas antigeninpersonalizedpeptidevaccine correspond-ingtotheKRAS mutationspresent in thetumor(Wedén etal., 2011). A phase II adjuvant trial considered 176 KRAS mutant, R0–R1resected, PDACpatientsenrolled toreceive placebo and gemcitabineorGI4000(awhole,heath–killedrecombinantS. cere-visiaeyeastexpressingamutatedRASprotein)andgemcitabine (Muscarellaetal.,2012).PrimaryendpointwasRFS.Onlyresultsin 39patientswithR1resectionwerepresented.TheGI4000group showedan11.4weekadvantageinmOS,a16%advantagein1year survival(72%vs56%)anda4.6weekadvantageinmRFS.Authors concludedthatGI-4000plusgemcitabineshowedanimprovement onsurvivalinR1subjectswithRASmutantPDAC.
Hyperacuteimmunotherapy is based onthehypothesis that some antigens presented ad hoc to the immune system (vac-cines)areabletotriggerapowerfulimmuneresponseknownas hyperacute rejection.Thislatter characteristically targets xeno-transplantedtissue,butinthiscaseitcanreactagainstmodified cancer cells. This inflammatory reaction/immune response is thoughttoberesponsiblefortheproductionofimmunityagainst tumorantigens(Saif,2011).Thesevaccinesmaybemadeofwhole cells,proteins,peptidesorDNAencodingtumorantigens.There are at least two vaccines in an advanced phase of evaluation fortheadjuvantsettingofPDACpatients.ThefirstistheG-VAX −pancreasvaccine thatconsistsof irradiatedcells stably trans-fectedtoexpressGM-CSF.Thisvaccinehasbeentestedinaphase IItrialamong60patientswithresectedPDAC,incombinationwith 5-FUbasedCRT.ThevaccinewaswelltoleratedwithmDFSand mOSof 17.3monthsand 24.8months, respectively;the1-year OSwas85%(Lutzetal.,2011).Thesecondisthe algenpantucel-Lvaccine thatconsistsof 2 irradiatedallogenicPDAC celllines (HAPa-1and HAPa-2) transfected toexpressmurine alpha-1,3-galactosyltransferase(alpha-GT). The murinealpha-GT epitopes arenotpresentinhumancellsandtheycaninduceahyperacute rejectionofvaccinepancreaticcancercellallografts.Thebinding ofpre-existinghumanantialpha-GTantibodies(whichnaturally occuragainstgutflora)tomurinealpha-GTepitopesresultsina rapidactivationofantibody–dependentcell-mediatedcytotoxicity towardallograftcells (Saif,2011;Cid-ArreguiandJuarez,2015). Aphase IIclinicaltrial,employingalgenpantucel-L, enrolled70 patientswithresected PDACto receive gemcitabineand 5-FU-basedCRTaswellasalgenpantucel-L(Hardacreetal.,2013).After amedianfollow upof21months,the12monthsDFSwas62% whereasthe12monthOSwas86%.Basedontheseencouraging results,aphaseIIIclinicaltrial(IMPRESS)hasbeenrecently
con-cludedwiththeaimtoassessOSafteraregimenofadjuvanttherapy (gemcitabinealoneorincombinationwith5-FUbasedCRT)with orwithoutalgenpantucel-Limmunotherapy(NCT01072981,2016). Thistrialdidnotachievetheprimaryendpoint,sinceno statisti-callysignificantdifferenceshavebeenreportedintermsofmOS (30.4and27.3monthsforthecontrolandalgenpantucel-Ltreated groups,respectively)andlong-termsurvival(3yearOSof41.4% and42.1%and4-yearOSof32.6%and32.7%forthe chemother-apyandchemotherapyplusalgenpantucel-Lgroups,respectively) (NewLinkGeneticsCorporation,2016).
AttheASCO2016meeting,ina multicenternonrandomized phase IIstudy (Yamaue et al.,2016)a peptidevaccine cocktail namedOCV-C01withpeptidesderivedfromKIF20A,VEGFR1,and VEGFR2 combined withgemcitabinewas tested in 30 resected PDAC patients. At every cycle, patients received subcutaneous injectionof 1mL of OCV-C01on days, 1, 8, 15, and 22 for 12 cycles,andintravenously1000mg/m2gemcitabineondays,1,8, and15for24weeks.ThissafecombinationachievedamDFSof15.8 months(CI95%:11.1–20.6)withaDFSrateat18monthsof34.6% (CI95%:18.3–51.6).MedianOSisstillnotreachedbutOSrateat18 monthwas69%(CI95%:48.8–82.5).Moreover,patientswithstrong cytotoxicTlymphocytesspecificresponseagainstKIF20Ashowed a more statistical significant mDFS. Four R0 resected patients expressingKIF20AdisplayednorecurrenceofPDAC,withaDFS significantlylongerthanotherR0resectedpatientsnotexpressing KIF20Aexpression(p=0.011).
Inconclusion,bothmoleculartargetagentsand immunother-apyseemtobeinterestingapproachesinthefieldofmultimodal treatmentofresectablePDAC,evenifmoreclinicaltrialsare nec-essary.
7. NeoadjuvanttherapyinresectablePDAC
In the last years, a preoperative approach wasstudied as a strategy for resectable PDAC patients in order to treat earlier micro-metastaticdisease,toincreaselong-termsurvival,toavoid morbidityandmortalityofsurgeryinpatientswithearlyrelapse, toevaluatetumorresponse,andtoimprovetreatmenttolerability (Silvestrisetal.,2016).Eveniftherearemanytheoretical bene-fitsforthisapproach,thereisstilllimitedevidenceonthistopic andsomepotentialhurdlesshouldbeevaluated,suchasapossible missedopportunityforresection,theneedoftreatmentfor symp-tomsofbiliaryorintestinalocclusion,andtheabsenceofsurgical staging.
There are few trials with the use of chemotherapy alone (Table 5).Palmeret al.randomized 50patientswithresectable PDACtoreceivegemcitabinealone or incombination with cis-platin(Palmeretal.,2007).Ahigherresectionratewasobserved in the combination arm (70%) compared to gemcitabine alone (38%). ThemOSswere15.6and 9.9 monthswitha 1-year sur-vivalrateof62%and42%forthecombinationarmandthecontrol arm,respectively.Thedataofthisstudyshouldberegardedwith cautionbecauseofthesmallsamplesizeandthepresenceof mis-diagnosis(pathologicalexaminationshowedthat12%ofpatients treatedwithgemcitabineand19%withthecombinationhadnot receivedadiagnosisofadenocarcinoma).AnotherphaseIIstudy evaluated28patientswithresectabledisease,whoreceived cis-platinincombinationwithgemcitabineasneoadjuvanttreatment (Heinrich et al., 2008). Therewas the recording of one partial response(PR)(4%),with61%ofstabledisease(SD).Globally, resec-tionratewas89%with71%ofR0resectionsanda mOSof19.1 monthsforresectedpatients.Tajimaetal.recentlyreportedthe resultsofthecombinationofgemcitabineandS-1in13patients (Tajimaetal.,2013).Theyobserved2PRand9SD.Anotherphase IItrial,conductedon38patientswithresectabledisease,
evalu-Table5
Prospectivestudiesofneoadjuvantchemotherapy.
Design N.pts Regimen Resectionrate(%) mOS(months) Ref.
RandomizedphaseII 2426 GemcitabineGemcitabine+cisplatin 3870 9.932 Palmeretal.(2007)
PhaseII 21a Gemcitabine+cisplatin 80 19.1a Heinrichetal.(2008)
PhaseI 13 Gemcitabine+S-1 85 NR Tajimaetal.(2013)
PhaseII 38 Gemcitabine+oxaliplatin 71 27.2 O’Reillyetal.(2014)
N.pts:numberofpatients;mOS:medianoverallsurvival.
aDatabasedonasubgroupofthewholepopulationincludedinthestudy.
atedneoadjuvantchemotherapywithgemcitabineandoxaliplatin. Thirtyfiveofthemcompletedthetreatmentprotocol.Theprimary endpointofthestudywas18-monthsurvivalwhichwasachieved in63%ofpopulation,withamOSof27.2months(O’Reillyetal., 2014).
AsregardsCRT,anMDAndersonretrospectiveanalysisshowed thattheuseofpreoperativeCRTwasassociatedwithabetter out-comeinresectablepatients.Relevantclinicaldataisrepresented bytheobservationofaregionaland/ordistantprogressionat pre-operativestagingin25%ofcases,suggestingalackofbenefitfrom anupfrontsurgeryinthissubgroupofpatients(Breslinetal.,2001). FewAuthorshaveprospectivelyevaluatedtherole ofCRTin this setting. Varadhachary et al., (2007) conducted a study of chemotherapywithgemcitabineandcisplatinfollowedby gem-citabinebasedCRT(Varadhacharyetal.,2008).Ofthe90patients enrolled,79(88%)completedtheintegratedtreatment.ThemOS ofthelatterwas18.7months,withamedianof31monthsin52 patientswhounderwentsurgery,comparedto10.5monthsinthe groupofnotresectedpatients(p<0.001).
Three studies including 189 patients were evaluated in a meta-analysis(Xuetal.,2014)whichcomparedneoadjuvantCRT vs postoperativeCRT. Thepooled HR of0.93 (CI95%: 0.69–1.25; p=0.62) did not document a benefit from neoadjuvant CRT in thissetting.Furthermore,tworandomizedtrialswereconducted, aimedat assessingtheimpactofneoadjuvantCRTcomparedto surgeryupfront.Bothstudieswereinterruptedprematurelydueto thelackofdifferencesintermsofdifferencesofR0resectionrate (Casadeietal.,2015)orthelowrecruitmentrate(Golcheretal., 2015).
An ongoing phase III trial is comparing preoperarive CRT vs surgeryalone (NCT01900327,2016NCT, 2016eNCT01900327, 2016). Moreover,anotherongoing phase IIIstudywillbe com-paringperioperative therapy followed by surgery and adjuvant therapytosurgeryfollowedbyadjuvanttherapy(NCT01314027, 2016).Later a three armsmulticenter Italian Phase II–III study willrandomizeperioperativechemotherapy(PELF)withthesame chemotherapyappliedpostoperatively andpostoperative gemc-itabine(NCT01150630,2016).
Consideringtheavailableevidencesofneoadjuvanttreatment forresectablePDAC,theroleofthisapproachneedstobevalidated inlarge,controlledrandomizedtrialscomparedtosurgeryfollowed bystandardadjuvantchemotherapy.ASCOguidelinesrecommend thatatotalof6monthsofadjuvanttherapy(including preoper-ativeregimen) beproposedaccordingtoan extrapolationfrom adjuvanttrials(Khoranaetal.,2016).Onecriticalclinicalissueis thedifficultassessmentoftreatmentresponse,likelyowingtothe densestromalcomponentofPDACwhichremainsradiographycally unchangedevenwhenhistologicalresponseisreported(Verbeka etal.,2015).Inthissettingofpatients,theuseofrestagingimaging shouldprimarlybeperformedtoidentifylocalordistantdisease progressionin combinationwiththeevaluationof performance statusandmodificationsofCa19.9levels.
8. Conclusions
After a timing preoperative staging focused on both the researchofdistantmetastasesandtheassessmentoflocal vascu-larinvolvement,surgeryrepresentstheinitialtherapeuticoption forresectablePDACpatients.Accordingtotheavailableevidences, 6monthsofmonochemotherapywithgemcitabineor5-FU rep-resentthestandardadjuvanttreatment.Similarlytosurgery,the relevance of thecentre where thepatient underwent adjuvant chemotherapyhasbeenreportedaswell.Today,itispremature to drawconclusion onthe potentialadvantage of combination chemotherapybecausetheywoulddependontheresultsof ESPAC-4 and onthe data fromrandomized phase IIItrials evaluating FOLFIRINOXandgemcitabine/nab-paclitaxel,whicharecurrently ongoing. Results of studies evaluating the role of CRT are dis-appointing, since it did not improve survival compared with chemotherapyalone,butitcouldreducelocalrecurrence improv-ing the QoL which could be a clinical relevant endpoint for these patients. Howto selectinitially resectable PDACpatients toimmediate surgery or preoperativechemotherapy remains a challenge.Probably,thisdecisionshouldbeprioritizedbytesting moreeffectivesystemicregimensandassesingclinico-pathological features and biomarker studies. In fact, fully-standardized and widely-sharedhistopathologicalandliquidbiopsytestswithlarger prospective validation studies are needed for discovering pre-dictive biomarkers, essential in understanding the biology of thismalignancy.Dependingontheresultsoftheinvestigational studiesevaluating therole of novelmodalities ofradiotherapy, immunotherapiesandothermoleculartargetapproaches,a mul-tidisciplinary approach can offer thebest address Chesignifica “address”?therapyforthesepatients.
Authorcontributions
NSand OBinstructedanddesignedtheoriginalconcept,and revisedthemanuscriptcritically.MF,MR,MS,ASandSCdrafted themanuscript, andrevisedit critically.EV,VV, AC,FC,IC,and GAsearchedliteraturesandrevisedthemanuscriptcritically.SP, ACG,AGMandVLdraftedthemanuscript.Allauthorscontributed toreviewandeditingofthemanuscript,andapprovedthefinal versiontobesubmitted.
Conflictofinterest
theAuthorsofthismanuscriptdeclaretheabsenceofconflictof interests.
Fundings
Nofundingstobedeclared. References
AIOMGuidelines,2015.Adenonocarcinomapancreatico.In:Versione,http://www. aiom.it/area+pubblica/area+medici/Prodotti+scientifici/linee+guida/1333
Ahn,D.H.,Williams,T.M.,Goldstein,D.A.,El-Rayes,B.,Bekaii-Saab,T.,2016. Adjuvanttherapyforpancreascancerinaneraofvaluebasedcancercare. CancerTreat.Rev.42,10–17,http://dx.doi.org/10.1016/j.ctrv.2015.11.004. Ansari,D.,Gustafsson,A.,Andersson,R.,2015.Updateonthemanagementof
pancreaticcancer:surgeryisnotenough.WorldJ.Gastroenterol.21, 3157–3165,http://dx.doi.org/10.3748/wjg.v21.i11.3157.
Bailey,P.,Chang,D.K.,Nones,K.,Johns,A.L.,Patch,A.M.,Gingras,M.C.,etal.,2016. Genomicanalysesidentifymolecularsubtypesofpancreaticcancer.Nature 531,47–52,http://dx.doi.org/10.1038/nature16965.
Bakkevold,K.E.,Arnesjø,B.,Dahl,O.,Kambestad,B.,1993.Adjuvantcombination chemotherapy(AMF)followingradicalresectionofcarcinomaofthepancreas andpapillaofVater-resultsofacontrolled,prospective,randomised multicentrestudy.Eur.J.Cancer29,698–703,http://dx.doi.org/10.1016/ S0959-8049(05)80349-1.
Barugola,G.,Partelli,S.,Marcucci,S.,Sartori,N.,Capelli,P.,Bassi,C.,etal.,2009. Resectablepancreaticcancer:whoreallybenefitsfromresection?Ann.Surg. Oncol.16,3316–3322,http://dx.doi.org/10.1245/s10434-009-0670-7. Barugola,G.,Partelli,S.,Crippa,S.,Butturini,G.,Salvia,R.,Sartori,N.,etal.,2013.
Timetrendsinthetreatmentandprognosisofresectablepancreaticcancerina largetertiaryreferralcentre.HPB(Oxford)15,958–964,http://dx.doi.org/10. 1111/hpb.12073.
Bockhorn,M.,Uzunoglu,F.G.,Adham,M.,Imrie,C.,Milicevic,M.,Sandberg,A.A., etal.,2014.Borderlineresectablepancreaticcancer:aconsensusstatementby theInternationalStudyGroupofPancreaticSurgery(ISGPS).Surgery155, 977–978,http://dx.doi.org/10.1016/j.surg.2014.02.001.
Boeck,S.,Hinke,A.,Wilkowski,R.,Heinemann,V.,2007.Importanceof performancestatusfortreatmentoutcomeinadvancedpancreaticcancer. WorldJ.Gastroenterol.13,224–227,http://dx.doi.org/10.3748/wjg.v13.i2.224. Bosman,F.T.,2010.WorldHealthOrganization,InternationalAgencyforResearch
onCancer.WHOclassificationoftumousofthedigestivesystem.Lyon: InternationalAgencyforResearchonCancer,https://www.iarc.fr/en/ publications/pdfs-online/pat-gen/bb2/BB2.pdf(accessed08.30.16.),417p. Bowenge,M.,Cellini,F.,Silvestris,N.,Cilla,S.,Deodato,F.,Macchia,G.,etal.,2015.
Roboticradosurgeryinpancreaticcancer:asystematicreview.WorldJ. Gastroenterol.21,9420–9429.
Breslin,T.M.,Hess,K.R.,Harbison,D.B.,Jean,M.E.,Cleary,K.R.,Dackiw,A.P.,Wolff, R.A.,Abbruzzese,J.L.,Janjan,N.A.,Crane,C.H.,Vauthey,J.N.,Lee,J.E.,Pisters, P.W.,Evans,D.B.,2001.Neoadjuvantchemoradiotherapyforadenocarcinoma ofthepancreas:treatmentvariablesandsurvivalduration.AnnSurgOncol.8 (2),123–132.
Brunetti,O.,Russo,A.,Scarpa,A.,Santini,D.,Reni,M.,Bittoni,A.,etal.,2015. MicroRNAinpancreaticadenocarcinoma:predictive/prognosticbiomarkersor therapeutictargets?Oncotarget6,23323–23341,http://dx.doi.org/10.18632/ oncotarget.4492.
Butturini,G.,Stocken,D.D.,Wente,M.N.,Jeekel,H.,Klinkenbijl,J.H.,Bakkevold,K.E., etal.,2008.Influenceofresectionmarginsandtreatmentonsurvivalin patientswithpancreaticcancer:meta-analysisofrandomizedcontrolledtrials. Arch.Surg.143,75–83,http://dx.doi.org/10.1001/archsurg.2007.17,discussion 83.
Casadei,R.,DiMarco,M.,Ricci,C.,Santini,D.,Serra,C.,Calculli,L.,etal.,2015. Neoadjuvantchemoradiotherapyandsurgeryversussurgeryalonein resectablepancreaticcancer:asingle-centerprospective,randomized, controlledtrialwhichfailedtoachieveaccrualtargets.J.Gastrointest.Surg.19, 1802–1812,http://dx.doi.org/10.1007/s11605-015-2890-4.
Cid-Arregui,A.,Juarez,V.,2015.Perspectivesinthetreatmentofpancreatic adenocarcinoma.WorldJ.Gastroenterol.21,9297–9316,http://dx.doi.org/10. 3748/wjg.v21.i31.9297.
Conroy,T.,Desseigne,F.,Ychou,M.,Bouché,O.,Guimbaud,R.,Bécouarn,Y.,etal., 2011.FOLFIRINOXversusgemcitabineformetastaticpancreaticcancer.N. Engl.J.Med.364,1817–1825,http://dx.doi.org/10.1056/NEJMoa1011923. DalMolin,M.,Zhang,M.,deWilde,R.F.,Ottenhof,N.A.,Rezaee,N.,Wolfgang,C.L.,
etal.,2015.Verylong-termsurvivalfollowingresectionforpancreaticcancer isnotexplainedbycommonlymutatedgenes:resultsofwhole-exome sequencinganalysis.Clin.CancerRes.21,1944–1950,http://dx.doi.org/10. 1158/1078-0432.CCR-14-2600.
DiMarco,M.,Grassi,E.,Durante,S.,Vecchiarelli,S.,Palloni,A.,Macchini,M.,etal., 2016.Stateoftheartbiologicaltherapiesinpancreaticcancer.WorldJ. Gastrointest.Oncol.8,55–66,http://dx.doi.org/10.4251/wjgo.v8.i1.55. Edge,S.B.,2010.AmericanJointCommitteeonCancerAJCCCancerStagingManual,
xiv.Springer,NewYork,London,https://cancerstaging.org/references-tools/ deskreferences/Documents/AJCC6thEdCancerStagingManualPart1.pdf
(accessed08.30.16.),648p.
Fensterer,H.,Schade-Brittinger,C.,Müller,H.H.,Tebbe,S.,Fass,J.,Lindig,U.,etal., 2013.MulticenterphaseIItrialtoinvestigatesafetyandefficacyofgemcitabine combinedwithcetuximabasadjuvanttherapyinpancreaticcancer(ATIP). Ann.Oncol.24,2576–2581,http://dx.doi.org/10.1093/annonc/mdt270. Ferrone,C.R.,Finkelstein,D.M.,Thayer,S.P.,Muzikansky,A.,Fernandez-delCastillo,
C.,Warshaw,A.L.,2006.PerioperativeCA19-9levelscanpredictstageand survivalinpatientswithresectablepancreaticadenocarcinoma.J.Clin.Oncol. 24,2897–2902,http://dx.doi.org/10.1200/JCO.2005.05.3934.
Fiorini,C.,Cordani,M.,Padroni,C.,Blandino,G.,DiAgostino,S.,Donadelli,M.,2015. Mutantp53stimulateschemoresistanceofpancreaticadenocarcinomacellsto gemcitabine.Biochim.Biophys.Acta1853,89–100,http://dx.doi.org/10.1016/j. bbamcr.2014.10.003.
Garcea,G.,Dennison,A.R.,Ong,S.L.,Pattenden,C.J.,Neal,C.P.,Sutton,C.D.,etal., 2007.Tumourcharacteristicspredictiveofsurvivalfollowingresectionfor
ductaladenocarcinomaoftheheadofpancreas.Eur.J.Surg.Oncol.33, 892–897,http://dx.doi.org/10.1016/j.ejso.2007.02.024.
Garrido-Laguna,I.,Hidalgo,M.,2015.Pancreaticcancer:fromstate-of-the-art treatmentstopromisingnoveltherapies.Nat.Rev.Clin.Oncol.12,319–334,
http://dx.doi.org/10.1038/nrclinonc.2015.53.
Georgiadou,D.,Sergentanis,T.N.,Sakellariou,S.,Filippakis,G.M.,Zagouri,F., Vlachodimitropoulos,D.,etal.,2014.CyclinD1,p16(INK)(4A)andp27(Kip1) inpancreaticadenocarcinoma:assessingprognosticimplicationsthrough quantitativeimageanalysis.APMIS122,1230–1239,http://dx.doi.org/10. 1111/apm.12289.
Giovinazzo,F.,Turri,G.,Katz,M.H.,Heaton,N.,Ahmed,I.,2016.Meta-analysisof benefitsofportal-superiormesentericveinresectioninpancreaticresection forductaladenocarcinoma.Br.J.Surg.103,179–191,http://dx.doi.org/10. 1002/bjs.9969.
Glant,J.A.,Waters,J.A.,House,M.G.,Zyromski,N.J.,Nakeeb,A.,Pitt,H.A.,etal.,2011. Doestheintervalfromimagingtooperationaffecttherateofunanticipated metastasisencounteredduringoperationforpancreaticadenocarcinoma? Surgery150,607–616,http://dx.doi.org/10.1016/j.surg.2011.07.048. Golcher,H.,Brunner,T.B.,Witzigmann,H.,Marti,L.,Bechstein,W.O.,Bruns,C.,
etal.,2015.Neoadjuvantchemoradiationtherapywithgemcitabine/cisplatin andsurgeryversusimmediatesurgeryinresectablepancreaticcancer:results ofthefirstprospectiverandomizedphaseIItrial.Strahlenther.Onkol.191, 7–16,http://dx.doi.org/10.1007/s00066-014-0737-7.
Goonetilleke,K.S.,Siriwardena,A.K.,2007.Systematicreviewofcarbohydrate antigen(CA19-9)asabiochemicalmarkerinthediagnosisofpancreatic cancer.Eur.J.Surg.Oncol.33,266–270,http://dx.doi.org/10.1016/j.ejso.2006. 10.004.
Greenhalf,W.,Ghaneh,P.,Neoptolemos,J.P.,Palmer,D.H.,Cox,T.F.,Lamb,R.F., etal.,2014.PancreaticcancerhENT1expressionandsurvivalfrom
gemcitabineinpatientsfromtheESPAC-3trial.J.Natl.CancerInst.106,djt347,
http://dx.doi.org/10.1093/jnci/djt347.
Grochola,L.F.,Taubert,H.,Greither,T.,Bhanot,U.,Udelnow,A.,Würl,P.,2011.
ElevatedtranscriptlevelsfromtheMDM2P1promoterandlowp53transcript levelsareassociatedwithpoorprognosisinhumanpancreaticductal adenocarcinoma.Pancreas40,265–270.
Haider,S.,Wang,J.,Nagano,A.,Desai,A.,Arumugam,P.,Dumartin,L.,etal.,2014.A multi-genesignaturepredictsoutcomeinpatientswithpancreaticductal adenocarcinoma.GenomeMed.6,105, http://dx.doi.org/10.1186/s13073-014-0105-3.
Hammel,P.,Huguet,F.,VanLaethem,J.L.,Goldstein,D.,Glimelius,B.,Artru,P., etal.,2013.Comparisonofchemoradiotherapyandchemotherapyinpatients withalocallyadvancedpancreaticcancercontrolledafter4monthsof gemcitabinewithorwithouterlotinib:finalresultsoftheinternationalphase IIILAP07study.J.ClinicOncol.(accessed08.30.16.)Suppl.abstr.4003http:// meetinglibrary.asco.org/content/116391-132.
Hardacre,J.M.,Mulcahy,M.,Small,W.,Talamonti,M.,Obel,J.,Krishnamurthi,S., etal.,2013.Additionofalgenpantucel-Limmunotherapytostandardadjuvant therapyforpancreaticcancer:aphase2study.J.Gastrointest.Surg.17, 94–100,http://dx.doi.org/10.1007/s11605-012-2064-6.
Hartwig,W.,Hackert,T.,Hinz,U.,Gluth,A.,Bergmann,F.,Strobel,O.,etal.,2011. Pancreaticcancersurgeryinthenewmillennium:betterpredictionof outcome.Ann.Surg.254,311–319,http://dx.doi.org/10.1097/SLA. 0b013e31821fd334.
Heinrich,S.,Pestalozzi,B.C.,Schäfer,M.,Weber,A.,Bauerfeind,P.,Knuth,A.,etal., 2008.ProspectivephaseIItrialofneoadjuvantchemotherapywith gemcitabineandcisplatinforresectableadenocarcinomaofthepancreatic head.J.Clin.Oncol.26,2526–2531,http://dx.doi.org/10.1200/JCO.2007.15. 5556.
Herman,J.M.,Swartz,M.J.,Hsu,C.C.,Winter,J.,Pawlik,T.M.,Sugar,E.,etal.,2008. Analysisoffluorouracil-basedadjuvantchemotherapyandradiationafter pancreaticoduodenectomyforductaladenocarcinomaofthepancreas:results ofalarge,prospectivelycollecteddatabaseattheJohnsHopkinsHospital.J. Clin.Oncol.26,3503–3510,http://dx.doi.org/10.1200/JCO.2007.15.8469. Hu,H.,Hang,J.J.,Han,T.,Zhuo,M.,Jiao,F.,Wang,L.W.,2016.TheM2phenotypeof
tumor-associatedmacrophagesinthestromaconfersapoorprognosisin pancreaticcancer.TumourBiol.(January6), http://dx.doi.org/10.1007/s13277-015-4741-z(Epubaheadofprint).
Huang,J.,Löhr,J.M.,Nilsson,M.,Segersvärd,R.,Matsson,H.,Verbeke,C.,etal.,2015. Variantprofilingofcandidategenesinpancreaticductaladenocarcinoma.Clin. Chem.61,1408–1416,http://dx.doi.org/10.1373/clinchem.2015.238543. Huebner,M.,Kendrick,M.,Reid-Lombardo,K.M.,Que,F.,Therneau,T.,Qin,R.,etal.,
2012.Numberoflymphnodesevaluated:prognosticvalueinpancreatic adenocarcinoma.J.Gastrointest.Surg.16,920–926,http://dx.doi.org/10.1007/ s11605-012-1853-2.
Infante,J.R.,Matsubayashi,H.,Sato,N.,Tonascia,J.,Klein,A.P.,Riall,T.A.,etal., 2007.PeritumoralfibroblastSPARCexpressionandpatientoutcomewith resectablepancreaticadenocarcinoma.J.Clin.Oncol.25(3),319–325,http:// dx.doi.org/10.1200/JCO.2006.07.8824.
Izar,B.,Zhou,H.,Heist,R.S.,Azzoli,C.G.,Muzikansky,A.,Scribner,E.E.,etal.,2014. TheprognosticimpactofKRAS,itscodonandaminoacidspecificmutations, onsurvivalinresectedstageIlungadenocarcinoma.J.Thorac.Oncol.9, 1363–1369,http://dx.doi.org/10.1097/JTO.0000000000000266.
Jamieson,N.B.,Chan,N.I.,Foulis,A.K.,Dickson,E.J.,McKay,C.J.,Carter,C.R.,2013. Theprognosticinfluenceofresectionmarginclearancefollowing
pancreaticoduodenectomyforpancreaticductaladenocarcinoma.J.
