• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 7
  • 4
  • 3
  • 2
  • Tagged with
  • 31
  • 31
  • 16
  • 7
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Non-Syndromic atrioventricular septal defects: a refined definition, associated risk factors, and prognostic factors for left atrioventricular valve replacement following primary repair

Patel, Sonali Subhashchandra 01 December 2010 (has links)
Congenital heart defects (CHDs) constitute a major proportion of clinically significant birth defects and are an important component of pediatric cardiovascular disease. Atrioventricular septal defects (AVSDs) include a range of anomalies characterized by atrial, ventricular, and atrioventricular (AV) valve defects. AVSDs commonly occur in the presence of a syndrome, most frequently Down syndrome; they also occur in isolation and are referred to as non-syndromic AVSDs (NSAVSDs). These studies were performed to evaluate for presence of an intermediate phenotype in parents and siblings of a child with a NSAVSD, risk factors associated with NSAVSDs, and prognostic risk factors for left AV valve replacement following primary repair of an AVSD. It was shown that the mean body surface area-standardized AV septal length (AVSL) was significantly shorter in the NSAVSD parents and siblings than in parents and siblings of syndromic AVSD case and control children. Using age- and gender-adjusted body surface area-standardized AVSL, it was determined that there was evidence for two component distributions in parents and siblings of NSAVSD children, suggesting the presence of an intermediate. Broadening the definition of AVSD to include those with a shortened AVSL may increase the power of genetic association and mapping studies to identify susceptibility genes. Risk factors associated with NSAVSD were examined using the 1997-2005 National Birth Defects Prevention Study database. Mothers who actively smoked or were exposed to passive smoke anytime from one month prior to pregnancy through the end of the first trimester were more likely to have an infant with a NSAVSD. There was a suggestive association between AVSDs and use of antibacterial, antifungal, and antiviral medications. Additional investigations are warranted to investigate associations with specific medications as well as to uncover possible gene-environment interaction effects that may modify these risks in order to develop improved primary prevention strategies. Using the Pediatric Cardiac Care Consortium database, factors associated with time to first reoperation and time to replacement following primary AVSD repair were evaluated. Type of AVSD repair, closure of the mitral valve cleft, moderate to severe postoperative left AV valve regurgitation, and presence of postoperative complete heart block were associated with earlier time to reoperation after adjusting for age and weight at AVSD repair. Down syndrome and presence of postoperative mitral stenosis were associated with earlier time to replacement. Prognostic risk factors following left AV valve replacement in children who had previously undergone AVSD repair were also identified. A prosthetic valve size to body weight ratio of greater than 3 and the presence of Down syndrome were identified as predictors of in-hospital death following left AV valve replacement. By adding to our knowledge of the AVSD familial and environmental risk factors from these studies, we will be able to (1) improve genetic counseling, (2) identify other family members for genetic testing, (3) begin to devise primary prevention strategies, and (4) improve treatment modalities. By recognizing prognostic factors which influence survival, optimal patient care can be devised which will not only improve treatment modalities, but also long-term survival.
22

Expression der Cyclooxygenase-2 im Mammakarzinom

Müller, Berit Maria 12 April 2005 (has links)
Cyclooxygenasen regulieren die Produktion von Prostaglandinen und spielen eine Rolle bei der Entstehung und Progression maligner Tumore. Versuche mit COX Inhibitoren (NSAIDs) zeigten im Tiermodell eine deutliche Reduktion von Inzidenz und Größe der Tumoren in einer dosisabhängigen Weise. Das Ziel der vorliegenden Arbeit war, das Expressionsmuster der induzierbaren Isoform COX-2 und der konstitutiven Isoform COX-1 im Mammakarzinom zu untersuchen. Die Grundlage der Untersuchung bildeten Tumorproben von 221 Patientinnen mit primärem Mammakarzinom. Diese wurden mittels immunhistochemischer Methoden auf beide COX-Isoenzyme untersucht. Eine erhöhte COX-2 Expression wurde in 36% der untersuchten Mammakarzinome festgestellt. Sie korrelierte signifikant mit verschiedenen klinisch-pathologischen Parametern, insbesondere mit einem positiven Lymphknotenstatus, einer geringen Differenzierung und einer Tumorgröße >20 mm. Eine erhöhte COX-1 Expression wurde in 45% der untersuchten Tumoren gefunden und korrelierte signifikant mit kleineren und nicht in regionäre Lymphknoten metastasierten Karzinomen. In der univariaten Überlebensanalyse stellte sich eine positive COX-2 Expression im Gegensatz zur COX-1 sowohl im rezidivfreien Überleben als auch im Gesamtüberleben als prognostisch relevant heraus. In der multivariaten Analyse erreichte eine erhöhte COX-2 Expression eine grenzwertige statistische Signifikanz als unabhängiger Parameter innerhalb des rezidivfreien Überlebens. Eine erhöhte COX-1 Expression erreichte keinen statistisch signifikanten Einfluß auf die Prognose. Aufgrund dieser Ergebnisse ist somit eine erhöhte COX-2 Expression im Mammakarzinom mit prognostisch ungünstigen Faktoren assoziiert. Inwieweit selektive COX-2 Inhibitoren als Therapeutika geeignet sind, werden die Ergebnisse weiterer Studien zeigen. / Cyclooxygenases regulate the production of prostaglandins and play a role in tumor development and progression. COX-inhibitors (NSAIDs) showed a significant reduction of tumor incidence and tumor size in rodent models. In this study, we investigated the prognostic impact of expression of both COX-isoforms as well as the association of COX expression and other clinicopathological parameters in primary breast cancer. The expression of COX-1 and –2 was determined by immunohistochemistry retrospectivly in a cohort of 221 women. An elevated expression of COX-2 as the inducible form of the cyclooxygenases was detected in 36% of tumors and was significantly associated with several clinicopathological parameters, for example positive nodal status, poor differentiation and larger tumor size. In contrast, an increased expression of COX-1 was detected in 45% of breast carcinomas and was associated with smaller tumor size and negative nodal status. In univariate survival analysis a significant association between an increased expression of COX-2 and a decreased disease-free survival as well as decreased overall survival was found. An elevated expression of COX-1 had no significant influence on patient prognosis. The data of this study show a prognostic role of COX-2 expression. Further studies on selective COX-2 inhibitors will investigate their role in treatment of patients with breast cancer.
23

Natural history and prognostic factors in localized prostate cancer

Andrén, Ove January 2008 (has links)
<p>The natural history of localized prostate cancer is not fully understood. In most patients the tumor will never progress to a lethal disease, while a subset of patients will ultimately die of the disease. Efficient tools to separate indolent from lethal disease is currently lacking which means that many patients will be offered treatment without any benefit, but still be at risk of experiencing treatment related side effects.</p><p>The aims of these studies were to get more insight into the natural history of untreated localized prostate cancer, to assess the prognostic value of established clinical parameters such as Gleason score, nuclear grade and tumor volume and, moreover, some new prognostic markers Ki-67, AMACR and MUC-1. We also aimed to study time trends in the detection of incidental tumors in Sweden.</p><p>Patients with localized disease (n=223) and no initial treatment were followed for 21 years. Most patients had a favorable outcome. However, a subset of patients developed lethal disease even beyond 15 years of follow-up and these patients define the group that may benefit most from treatment with curative intent. Patients with poorly differentiated tumors experienced a 9 time higher risk of dying in prostate cancer.</p><p>The studies on prognostic markers are based on a cohort of patients (n=253) with incidental prostate cancer detected by transurethral resection for presumed benign hyperplasia. All patients were left without initial treatment. Gleason grade, nuclear grade and tumor volume turned all out to be independent prognostic factors. MUC-1, AMACR and Ki-67 also carried prognostic information. However, after adjustment for Gleason grade, nuclear grade and tumor volume only MUC-1 and AMACR remained as statistically significant prognostic factors. When tested for sensitivity and specificity they all failed and, consequently, they seem to be of less value in daily practice for cancelling an individual patient regarding the choice of treatment.</p><p>Time trends in incidental prostate tumors in Sweden were analyzed in a cohort of patients with prostate tumors detected by transurethral resection (TUR-P). Through linkage of the national registration number (NRN) with several registers, e.g. the Swedish Cancer Registry, the National Inpatient registry and the Cause of Death Registry we identified, during the period 1970 through 2003, in total 23288 patients with incidental prostate cancer, who constituted the study group. As comparison group we choose all patients diagnosed with prostate cancer between 1970-2003 excluding those with incidental cancer, in total 112204 patients. Our result confirms earlier findings that there has been a dramatic change over time in incidence of incidental prostate cancers in Sweden, which parallels the introduction of prostate specific antigen. We also found that the cumulative incidence of prostate cancer death is high in the incidental group, opposing earlier findings that incidental tumours are a non-lethal disease.</p> / issn 1642-4063
24

Natural history and prognostic factors in localized prostate cancer

Andrén, Ove January 2008 (has links)
The natural history of localized prostate cancer is not fully understood. In most patients the tumor will never progress to a lethal disease, while a subset of patients will ultimately die of the disease. Efficient tools to separate indolent from lethal disease is currently lacking which means that many patients will be offered treatment without any benefit, but still be at risk of experiencing treatment related side effects. The aims of these studies were to get more insight into the natural history of untreated localized prostate cancer, to assess the prognostic value of established clinical parameters such as Gleason score, nuclear grade and tumor volume and, moreover, some new prognostic markers Ki-67, AMACR and MUC-1. We also aimed to study time trends in the detection of incidental tumors in Sweden. Patients with localized disease (n=223) and no initial treatment were followed for 21 years. Most patients had a favorable outcome. However, a subset of patients developed lethal disease even beyond 15 years of follow-up and these patients define the group that may benefit most from treatment with curative intent. Patients with poorly differentiated tumors experienced a 9 time higher risk of dying in prostate cancer. The studies on prognostic markers are based on a cohort of patients (n=253) with incidental prostate cancer detected by transurethral resection for presumed benign hyperplasia. All patients were left without initial treatment. Gleason grade, nuclear grade and tumor volume turned all out to be independent prognostic factors. MUC-1, AMACR and Ki-67 also carried prognostic information. However, after adjustment for Gleason grade, nuclear grade and tumor volume only MUC-1 and AMACR remained as statistically significant prognostic factors. When tested for sensitivity and specificity they all failed and, consequently, they seem to be of less value in daily practice for cancelling an individual patient regarding the choice of treatment. Time trends in incidental prostate tumors in Sweden were analyzed in a cohort of patients with prostate tumors detected by transurethral resection (TUR-P). Through linkage of the national registration number (NRN) with several registers, e.g. the Swedish Cancer Registry, the National Inpatient registry and the Cause of Death Registry we identified, during the period 1970 through 2003, in total 23288 patients with incidental prostate cancer, who constituted the study group. As comparison group we choose all patients diagnosed with prostate cancer between 1970-2003 excluding those with incidental cancer, in total 112204 patients. Our result confirms earlier findings that there has been a dramatic change over time in incidence of incidental prostate cancers in Sweden, which parallels the introduction of prostate specific antigen. We also found that the cumulative incidence of prostate cancer death is high in the incidental group, opposing earlier findings that incidental tumours are a non-lethal disease.
25

Avaliação da Apoptose e Produção de TNF-a no Câncer de mama: correlação com fatores prognósticos

Rogério Estevam Farias 01 January 2004 (has links)
A apoptose é um importante fator no crescimento do câncer de mama, tendo sido relacionada a progressão tumoral. Por outro lado, o fator de necrose tumoral alfa (TNF-&#945;) que é uma citocina mediadora da apoptose é reconhecida por ter citotoxicidade contra células malignas destes tumores. Neste estudo, a presença de células apoptóticas em tumores graus I, II e III foi investigada e comparada com outros fatores prognósticos estabelecidos do câncer de mama. A detecção in situ da apoptose em células tumorais foi investigada pelo método TUNEL e a produção de TNF-&#945;, proliferação celular, receptores hormonais, expressão dos genes c-erbB-2 e p53 foram analisados utilizando-se procedimento imunoistoquímico. Nossos dados demonstraram que alto índice apoptótico esta relacionado a maiores níveis de proliferação, a expressão de p53, a tumores pouco diferenciados e a negatividade para receptores hormonais. Entretanto, quando analisados somente em tumores grau III, pacientes com história clínica de recidiva e metástase apresentaram menores níveis de apoptose, maiores índices prolifertivos e menor expressão de TNF-&#945; no infiltrado associado ao tumor. Estes achados indicam que em tumores grau III o número de células em apoptose está diretamente relacionado a um comportamento tumoral agressivo. Adicionalmente, foi observado maior expressão de TNF-&#945; no infiltrado inflamatório associado ao tumor e maior índice apoptótico pode estar relacionado a ausência de expansão ganglionar e recidiva do câncer de mama. / Tumor necrosis factor alpha (TNF-&#945;) is a cytokine recognized as an important mediator of apoptosis process and also showed citotoxicity against breast malignant tumor cells. In the present study, the presence of tumor apoptotic cells was investigated in grade I, II and III invasive breast cancer and compared with another prognostic factors. In situ detection of tumor apoptotic cells was investigated by direct immuno-peroxidase of digoxigenin-labeled genomic DNA. The production of TNF&#945;, tumor cell proliferation, hormonal receptor, c-erbB-2 and p53 was investigated using immuhistochemical procedure. Our data demonstrated that patients with high apoptotic rate correlates with higher levels of cell proliferation, positive p53 expression, negative hormonal expression and high grade breast cancer. Otherwise patients with a clinical history of cancer recurrence and metastasis presented a lower number of cancer apoptotic cells, higher tumor proliferation rate and lower expression of TNF-&#945; by inflammatory cells than that observed among patients diagnosed with the same histopathological type of breast cancer but with absence of tumor recurrence and metastasis. Taken together the results suggested that the rate of apoptosis reflect degrees of histological breast cancer and correlates with another prognostic factors. In addition, it is also possible that TNF-&#945; produced by tumorassociated inflammatory cells play an important role in the control of apoptosis of breast cancer cells and clinical behavior.
26

Du rôle de facteurs cliniques, métaboliques, biologiques et thérapeutiques dans le pronostic des patients atteints d'un cancer bronchique non à petites cellules localement avancé, stade III

Berghmans, Thierry 03 March 2009 (has links)
Au travers d’études cliniques et biologiques, de méta-analyses et de revues systématiques de la littérature, nous avons étudié les CBNPC de stade III sur le plan thérapeutique et cherché des facteurs pronostiques pour la survie dans le but d’améliorer la classification internationale et, à terme, de permettre une meilleure prise en charge des patients inclus dans ce groupe hétérogène de tumeurs.<p>Dans le cadre d’essais randomisés, nous avons montré qu’un abord multimodal et multidisciplinaire permettait d’améliorer le pronostic des patients atteints d’un CBNPC de stade III. Le traitement des tumeurs non résécables implique une combinaison de chimiothérapie et de radiothérapie, dont l’administration concomitante doit être proposée aux patients aptes à la tolérer. La chimiothérapie doit être incluse dans le schéma thérapeutique des tumeurs potentiellement résécables. Elle permet une résection chirurgicale complète chez des patients sélectionnés dont la tumeur était initialement non résécable.<p>Nous avons déterminé que des caractéristiques cliniques (l’indice de performance et l’âge), biologiques (les taux sanguins de polynucléaires neutrophiles, d’hémoglobine et de plaquettes, la bilirubinémie) et propres à la tumeur (l’extension locale [T3-4] et ganglionnaire [N3]) avaient une valeur pronostique indépendante pour la survie. Ceci nous a permis d’aboutir à une proposition de modification de la classification internationale concernant les CBNPC de stade III.<p>Bien que pris individuellement, les facteurs biologiques que nous avons étudiés (p53, EGF-R, TTF-1, Mdm2) n’aient pas de valeur pronostique pour la survie, nous avons montré que la combinaison EGF-R+/TTF1- était un facteur pronostique indépendant en analyse multivariée pour la survie spécifique au cancer bronchique.<p>Nous avons finalement évalué le rôle pronostique de la tomodensitométrie par émission de positrons et de la mesure semi-quantitative de captation du 18F-FDG (SUV) sur la survie des patients atteints de CBNPC et montré qu’un SUV élevé était un facteur de mauvais pronostic pour la survie. / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished
27

Une étude des voies de signalisation impliquées dans la carcinogénèse et le traitement des fibromatoses agressives / A study of signaling pathways involved in carcinogenesis and treatment of aggressive fibromatosis

Dufresne, Armelle 06 June 2014 (has links)
Les fibromatoses agressives sont des tumeurs conjonctives rares, pouvant envahir les structures adjacentes parfois de manière très agressive et responsables de fréquentes récidives loco-régionales mais dépourvues de potentiel métastatique. Leur évolution est imprévisible. Actuellement, la stratégie de leur prise en charge est remise en cause et ces tumeurs sont de plus en plus souvent surveillées à leur diagnostic. En cas de tumeur évolutive, les traitements systémiques disponibles sont multiples mais d'efficacité variable. Aucun facteur pronostique de récidive ou d'évolutivité spontanée et aucun facteur prédictif d'efficacité des traitements médicaux n'a aujourd'hui été identifié. Les travaux de 2 premières publications ont étudié les facteurs cliniques de récidive après exérèse chirurgicale, et ont retenu le jeune âge du patient, la grande taille tumorale et sa localisation extra-abdominale comme étant de mauvais pronostic. Dans une 3ème publication, nous avons recherché si le sous-type moléculaire de mutation de CTNNB1 observé dans les fibromatoses sporadiques pouvait influencer la récidive: la mutation S45F est de moins bon pronostic que les autres. Un autre article rapporte les résultats de l'analyse des profils d'expression des miRNAs des fibromatoses qui semblent se corréler à leur pronostic mais cela doit être confirmé. Les 3 articles suivant présentent des travaux recherchant des facteurs prédictifs de réponse des fibromatoses à l'imatinib : l'expression d'aucune des cibles connues de l'imatinib n'a été retrouvée comme influençant significativement la réponse au traitement. Le rôle des variants M541L et V530I de l'exon 10 de KIT reste à déterminer / Aggressive fibromatoses is rare mesenchymal tumors, which could invade the neighboring structures sometimes in a very aggressive way and responsible of frequent locoregional recurrences but devoid of metastatic potential. Their evolution is unpredictable. At present, the strategy of their management is questioned and these tumors are more and more often watched after their diagnosis. In case of evolutionary tumor, the available systematic treatments are multiple but of variable efficiency. Any prognostic factor of recurrence or spontaneous evolution capacities and no predictive factor of efficiency of the medical treatments was identified today. The works of first 2 publications studied the prognostic clinical factors of recurrence after surgical excision, and held the young age of the patient, the big tumoral size and its extra-abdominal location as being of bad forecast. In a 3rd publication, we looked for if the molecular subcategory of CTNNB1 mutation observed in the sporadic fibromatoses could influence the recurrence: the S45F mutation is of less good forecast than the others. Another article reports the results of the analysis of the miRNAs expression profiles of the fibromatoses which seem to correlate in their forecast but this must be confirmed. The three following articles present works looking for predictive factors of response of fibromatoses to the imatinib: the expression of none of the known targets for the imatinib was not found as influencing significantly the response to the treatment. The role of the M541L and V530I variants of the exon 10 of KIT remains to determine
28

Androgen controlled regulatory systems in prostate cancer : potential new therapeutic targets and prognostic markers

Hammarsten, Peter January 2008 (has links)
BACKGROUND: Prostate cancer is by far the most common cancer among Swedish men. Some patients have an aggressive lethal disease, but the majority of affected men have long expected survival. Unfortunately, the diagnostic tools available are insufficient in predicting disease aggressiveness. Novel prognostic markers are therefore urgently needed. Furthermore, metastatic prostate cancer is generally treated with castration, but the long-term effects are insufficient. Additional studies are therefore needed to explore how the effects of this therapy can be enhanced. Prostate growth and regression is beside testosterone controlled by locally produced regulators. Vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) are two of the major regulators in the normal prostate and in prostate tumours. MATERIALS AND METHODS: VEGF and EGFR were explored in the prostate, by treating rats with either anti-VEGF or anti-EGFR treatment during castration and testosterone-stimulated prostate growth. Rats with implanted androgen-independent prostate tumours were treated with an inhibitor of both VEGF receptor-2 (VEGFR-2) and EGFR. Stereological techniques, immunohistochemistry, western blotting and quantitative real-time PCR were used to evaluate these experiments. Furthermore, prostate tissue from untreated prostate cancer patients was used to retrospectively explore the expression of phosphorylated-EGFR (pEGFR) in relation to outcome. RESULTS: Anti-VEGF treatment during testosterone-stimulated prostate growth, inhibited vascular and prostate growth. Anti-EGFR treatment during castration and testosterone-stimulated prostate growth resulted in enhanced castration effects and inhibited prostate growth. Anti-vascular treatment of androgen-independent prostate cancer with an inhibitor of VEGFR-2 and EGFR, that targets the normal and tumour vasculature, enhanced the effects of castration. Low immunoreactivity for pEGFR in prostate epithelial cells, both in the tumour and also in the surrounding non-malignant tissue, was associated with good prognosis. CONCLUSIONS: Anti-vascular treatment, with an inhibitor of VEGFR-2 and EGFR, in combination with castration could be an effective way to treat androgen-insensitive prostate tumours. VEGF and EGFR signalling are necessary components in testosterone-stimulated prostate growth. Phosphorylation of EGFR could be a useful prognostic marker for prostate cancer patients. Tumours may affect the surrounding non-malignant tissue and pEGFR immunoreactivity in the morphologically normal prostate tissue can be used to retrieve prognostic information.
29

Clinical and Experimental Studies in Peritoneal Metastases from Gastric Cancer

Hultman, Bo January 2013 (has links)
Gastric cancer (GC) is one of leading causes of death in the world, and peritoneal metastases (PM) are a major site of recurrence. PM from GC implies a poor prognosis, with median overall survival (mOS) approximately 3 months and no survival at five years. The aims of this thesis were to explore the incidence and evaluate prognostic factors for mOS of PM from GC in a defined population; to investigate the outcome of a new multimodal treatment; to analyse the treatment costs, and to investigate differences in drug sensitivity between individual patient samples and between various tumours. The incidence of loco-regional advanced GC was 3.8 per 100,000 person-years. Synchronous loco-regional GC in combination with synchronous distant metastasis was a negative prognostic factor while chemotherapy and good performance status, and radiotherapy plus chemotherapy were positive prognostic factors . There were no significant differences in mOS for the group of patients included during the period 2000-2004 versus 2005-2009, and this lack of improvement in mOS during the past decade justifies new treatment approaches. In a Phase II study of patients treated with neoadjuvant systemic chemotherapy followed by cytoreductive surgery + hyperthermic intraperitoneal chemotherapy, mOS was 14.3 months and for patients with macroscopically radical surgery mOS was 19.1 months. The mean overall cost of the loco-regional treatment was $145,700 compared to $59,300 with systemic chemotherapy treatment. In an ex vivo chemo-sensitivity test, it was determined that GC samples were equivalent to colorectal cancer in chemo-sensitivity to standard drugs and targeted drugs, whereas ovarian cancer samples were more sensitive. The individual GC samples varied considerably in sensitivity to increasing concentrations of the drugs, arguing for individualized drug selection. The incidence of loco-regional advanced GC was more common than previously reported and there were no improvements in mOS over the past decade. The mOS for patients with neoadjuvant systemic chemotherapy followed by macroscopically radical cytoreductive surgery + hyperthermic intraperitoneal chemotherapy was better than in recent reports on treatment with systemic chemotherapy. Treatment of advanced GC patients is costly irrespective of treatment modality. The GC samples varied considerably between individuals in terms of sensitivity to increasing concentrations of the drugs and were comparable to colorectal cancer in chemo-sensitivity.
30

Étude des distorsions du répertoire immunitaire en tant que facteur pronostique de risque chez les patientes souffrant d’un cancer du sein métastatique en 1ère rechute : étude de la valeur pronostique de la lymphopénie et de la divpénie / Study of distortions of the immune repertoire as a prognostic factor of risk in patients suffering from metastatic breast cancer in first relapse : study of the prognostic value of lymphopenia and divpenia

Manuel, Manuarii 05 March 2012 (has links)
Des travaux antérieurs de l’équipe ont démontré l’impact majeur de la lymphopénie (<1Giga/L), détectée avant tout traitement, sur la survie globale des patients atteints d’un cancer solide en phase métastatique, soulignant ainsi l’importance du système immunitaire dans le contrôle de la progression tumorale. Au cours de mon projet de thèse, j’ai analysé l’apport de la diversité combinatoire de la chaine β du TCR, autre indicateur de la qualité du système immunitaire, en tant que marqueur pronostique chez des patientes atteintes de cancer du sein en phase métastatique. J’ai pu montrer qu’un score combinant la diversité des TCR et le nombre de lymphocytes (score NDL) est un facteur indépendant de mauvais pronostic en analyse multivariée. Ce score permet l’identification d’une sous population de patientes à risque qui présente à la fois une lymphopénie et une faible diversité (< 33%) combinatoire du TCR et pour laquelle une très forte réduction de la médiane de survie est observée. Nous avons également réalisé une étude plus approfondie de l’impact des sous-populations de lymphocytes et des cytokines plasmatiques produites. En parallèle, j’ai été amené à développer des tests de biologie moléculaire pour améliorer l’étude de la diversité du répertoire des TCR au niveau génomique. Ces travaux nous ouvrent la voie vers de nouvelles stratégies thérapeutiques qui intégreraient les perturbations du système immunitaire. En effet, suite à ces résultats, un essai clinique basé sur l’administration d’IL-7, cytokine permettant l’expansion des cellules T avant ou pendant la chimiothérapie vient d’être activé au Centre Léon Bérard / Previous work of the team demonstrated the major impact of lymphopenia (<1Giga/L), detected before treatment, on overall survival of patients with solid metastatic cancer, highlighting the importance of immune system in controlling tumor progression. During my thesis project, I analyzed the contribution of the combinatorial diversity of the TCR β chain, another indicator of the quality of the immune system, as a prognostic marker in patients with metastatic breast cancer. I was able to show that a score combining the diversity of TCR and the number of lymphocytes (score NDL) is an independent factor of poor prognostic in multivariate analysis. This score allows identification of a subpopulation of patients at risk who has both a lymphopenia and a low combinatorial diversity (<33%) of TCR and for which a reduction in the median survival was observed. We also made further study of the impact of subpopulations of lymphocytes and plasma cytokines. In parallel, I developed molecular tests to improve the study of TCR repertoire diversity at the genomic level. This work opens the door to new therapeutic strategies that would consider immune system dysfunctions. Indeed, following these results, a clinical trial based on the administration of IL-7 cytokine for the expansion of T cells before or during chemotherapy has been activated at the Centre Léon Bérard

Page generated in 0.145 seconds