Estelle BRONSART mémoire DES 7_06_2016

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ETUDE!DE!LA!VALEUR!PRONOSTIQUE!DE!
L’INFILTRAT!LYMPHOCYTAIRE!DANS!UNE!
COHORTE!DE!77!PATIENTS!PORTEURS!DE!
GLIOBLASTOMES!TRAITES!par!
RADIOCHIMIOTHERAPIE!!
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Estelle!Bronsart!
Tuteurs : Dr Boone, Pr Ghiringhelli
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1!
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Résumé!
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L'expression! de! PD-L1! et! IL17! des! lymphocytes! infiltrant! les! tumeurs! sont! des! facteurs!
pronostiques!opposés!dans!le!glioblastome.!
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Le!glioblastome!(GBM)!est!la!plus!fréquente!des!tumeurs!cérébrales.!La!médiane!de!survie!
n’est!que!de!15!mois!malgré!les!récents!progrès!techniques!de!radiothérapie!et!l'association!du!
témozolomide! à! la! radiothérapie.! Les! lymphocytes! infiltrant! les! tumeurs! (TIL)! sont! présents!
dans! le! stroma!tumoral!glial! mais! leur! influence! sur! le! pronostic! des! patients! n'est! pas!
clairement!établie.!L'objectif!de! cette! étude! rétrospective!était!!d'étudier!la!valeur!pronostique!
de!l'infiltration!en! lymphocytes! ! IL17,! CD45! et! PD-L1!dans! une!cohorte!homogène! de!patients!
porteurs!d’un!GBM.!(
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Tous! les! patients! inclus! ont! bénéficié!d’une! biopsie! ou! d’une! chirurgie!suivie! d'une!
radiothérapie! associée! à! du! témozolomide! (protocole!de"Stupp").! Les! populations!
lymphocytaires! ! IL17,! CD45! et! PD-L1! ont! été! identifiées! par! immunohistochimie.! Les! cellules!
étaient!comptées!dans!des!champs!de!grossissement!!x!40.!Le!logiciel!Cutoff!Finder!a!été!utilisé!!
pour! déterminer! le! seuil! permettant! de! !séparer!les! infiltrats! faibles! ou! élevés.! Un! test! de!
Logrank!et!un!modèle!de!Cox!ont!été!utilisés!pour!déterminer!la!survie!globale!en!fonction!du!
type!et!de!la!densité!des!!lymphocytes!infiltrant!les!tumeurs.!
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L’étude! a! porté! sur! une! cohorte!homogène! !de! 77! patients!opérés! par! le! service! de!
neurochirurgie! du! CHU! d’Amiens! !et! traités! par! radiochimiothérapie! entre! 2006! et! 2013.! ! En!
analyse! univariée,! un! nombre! élevé! de! cellules! exprimant! IL17! est! corrélé!à! une! faible! survie!
globale! (HR=1,7!;! IC95! [1,1-1,9]!;! p=0,03).! Une! infiltration! élevée! en! lymphocytes! PD-L1! est!
corrélée!à!un!meilleur!pronostic!(survie!globale!15,3!mois!si!PD-L1<1%)!versus!24!mois!si!PD-
L1>1%).!Il!n’y!a!pas!de!relation!entre!le!marquage!des!lymphocytes!CD45!et!la!survie.!En!analyse!
multivariée,!une!infiltration!élevée!en!PD-L1!reste!un!facteur!pronostique!indépendant!associé!à!
une!meilleure!survie!(HR=0,4!;!!IC95![0,2-0,8]!;!p=0,06)!tout!comme!l'infiltration!élevée!en!IL17!
reste!associée!à!un!mauvais!pronostic!!(HR=2,6!;!IC95![1,4-5,3]!;!p=0,03).!
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Notre!étude! souligne! que! les! infiltrations! en! PD-L1! et! IL17! sont! associées! à! la! survie!
globale!dans!une!cohorte!de!77!patients!atteints!de!glioblastome!ayant!bénéficié!d'un!traitement!
optimal!associant!une!chirurgie!à!une!radiochimiothérapie.!Ces!données!confirment!l'intérêt!de!
tester!des!immunothérapies!dirigées!vers!PD-L1!et!IL17!dans!les!glioblastomes.!
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2!
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Abstract!(submitted!to#ESMO2016).#!
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Glioblastoma (GB) is the most frequent malignant primary brain tumor. Median overall
survival (OS) is only 15 months despite recent progress with the association of temozolomide
and radiotherapy. Tumor infiltrating lymphocytes (TIL) are present in GB stroma but their
influence on prognosis is not clearly defined. The purpose of this retrospective study was to
explore the prognostic value in GB of tumor infiltration by IL17 (interleukin 17), CD45 and
PD-L1 (programmed death ligand 1) expressing lymphocytes.
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All included patients had surgery followed by radiotherapy and temozolomide
(Stupp’sregimen). IL-17, CD45 and PD-L1 were assessed by immunohistochemistry in a
cohort of 77 GBM. Number of positive cells were count in a X40 field. We used the software
cutoff finder to determine the optimal cut off to separate patients with high or low infiltrate.
Logrank analysis and Cox proportional hazard models were used to determine overall survival
factors in function of type and number of TIL.
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In univariate analysis, high number of IL17 expressing cells was correlated with poor
OS (HR=1.7, IC [1.1-1.19], p=0.03). High PD-L1 infiltration was correlated with a better
prognosis (OS: 15.3 months if PD-L1 <1% vs 24 months if PD-L1>1%; p=0.05). IN contrast
CD45 is no associated with outcome. In multivariate analysis, high PD-L1 infiltration remain
independent factor was associated with a better survival (HR=0.4, IC95 [0.2-0.8], p=0.016)
and high IL17 infiltration of poor survival (HR=2.6, IC95 [1.4-5.3], p=0.03).
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This study underline that PDL1 infiltrate and IL-17 are associated with outcome in a
cohort of 77 patients with GBM that received an optimal treatment with surgery and
radiochemotherapy. Such data support rational to test PD-L1 and IL17 targeted
immunotherapy in GBM.
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3!
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Liste&des&abréviations!
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ADJ!=!adjuvant!
Cellule!NK!=!cellule!natural!killer!!
CPA!=!cellule!présentatrice!d'antigène!
CMH!=!complexe!majeur!d'histocompatibilité!
CTLA4!=!Cytotoxic!T!Lymphocyte!Associated!protein!4!
EGFR!=!Epidermal!Growth!Factor!Receptor!
FOXP3!=!Forkhead!box!protein!3!
Gy!=!Gray!
HR!=!hazard!ratio!
IDH1!=!Isocitrate!Deshydrogénase!1!
IFN!=!interféron!
IL17!=!interleukine!17!
IL2,!IL5...!=!interleukine!2,!interleukine!5...!
KF!=!Karnofsky!
LT!=!lymphocyte!T!
LTh!=!Lymphocyte!T!Helper!
LTreg!=!Lymphocytes!T!régulateurs!
MGMT!=!O-6-Méthylguanine-DNA-Méthyltransférase!
PD1!=!programmed!cell!death!protein!1!
PD-L1!=!programmed!cell!death!protein!ligand!1!
PTEN!=!Phosphatase!and!Tensing!homolog!
RC!macro!=!résection!complète!macrosopique!
RP!=!résection!partielle!
SIDA!=!Syndrome!de!l'Immunodéficience!Acquise!
TIL!=!Tumour!Infiltrating!Lymphocytes!
TMZ=!témozolomide!
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4!
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Liste&des&figures&et&tableaux!
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Figure!1!=!concept!de!l'immunoediting!en!3!phases:!élimination,!équilibre,!échappement!
Figure! 2! =! de! multiples! rétrocontrôles! inhibiteurs! ou! activateurs! modulent! l'activation! des!
lymphocytes!T!
Figure!3!=!propriétés!de!la!cellule!tumorale!
Figure!4!=!microenvironnement!tumoral!
Figure!5!=!tissu!tumoral!aux!grossissements!x!10!et!x!20!
Figure!6!=!lames!immunomarquées!au!grossissement!x!20!
Figure!7!=!probabilité!de!survie!en!fonction!d'IL17!
Figure!8!=!probabilité!de!survie!en!fonction!de!CD45!
Figure!9!=!probabilité!de!survie!en!fonction!de!PD-L1!
Figure!10!=!probabilité!de!survie!en!fonction!du!type!de!chirurgie!:!biopsie!vs!chirurgie!d'exérèse!
Figure!11!=!probabilité!de!survie!en!fonction!du!sexe!
Figure!12!=!combinaisons!thérapeutiques!possibles!avec!les!immunothérapies!
Tableau!1!=!caractéristiques!de!la!population!de!l'étude!
Tableau!2!=!analyse!multivariée!
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Remerciements!
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Pr!Sevestre,!service!d'anatomopathologie!CHU!Amiens!
Dr!Trudel,!service!de!biologie!moléculaire!CHU!Amiens!
Pr!Chauffert,!service!d'oncologie!médicale!CHU!Amiens!
Dr!Faraldi,!service!de!radiothérapie!CH!Compiègne!
Dr!Sallé,!service!de!radiothérapie!CH!Beauvais!
Dr!Picon,!service!de!radiothérapie!CH!Saint!Quentin!
Valentin!Derangère,!Centre!Georges!François!Leclerc!Dijon!
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