Long-term Outcome and Late Side Effects in Endometrial Cancer Patients Treated with Surgery and Postoperative Radiation Therapy.

BACKGROUND: We retrospectively reviewed the long-term outcome and late side effects of endometrial cancer (EC) patients treated with different techniques of postoperative radiotherapy (PORT). METHODS: Between 1999 and 2012, 237 patients with EC were treated with PORT. Two-dimensional external beam radiotherapy (2D-EBRT) was used in 69 patients (30 %), three-dimensional EBRT (3D-EBRT) in 51 (21 %), and intensity-modulated RT (IMRT) with helical Tomotherapy in 47 (20 %). All patients received a vaginal brachytherapy (VB) boost. Seventy patients (29 %) received VB alone. RESULTS: After a median of 68 months (range, 6-154) of follow-up, overall survival was 75 % [95 % confidence interval (CI), 69-81], disease-free survival was 72 % (95% CI, 66-78), cancer-specific survival was 85 % (95 % CI, 80-89), and locoregional control was 86 % (95 % CI, 81-91). The 5-year estimates of grade 3 or more toxicity and second cancer rates were 0 and 7 % (95 % CI, 1-13) for VB alone, 6 % (95 % CI, 1-11) and 0 % for IMRT + VB, 9 % (95 % CI, 1-17) and 5 % (95 % CI, 1-9) for 3D-EBRT + VB, and 22 % (95 % CI, 12-32) and 12 % (95 % CI, 4-20) for 2D-EBRT + VB (P = 0.002 and P = 0.01), respectively. CONCLUSIONS: Pelvic EBRT should be tailored to patients with high-risk EC because the severe late toxicity observed might outweigh the benefits. When EBRT is prescribed for EC, IMRT should be considered, because it was associated with a significant reduction of severe late side effects.

What energy level is required to avoid nutrient depletion after surgery in oropharyngeal cancer?

The rate of energy expenditure was repeatedly measured by indirect calorimetry both in the basal state (BMR) and in the resting fed state (RMR) in 8 middle-aged male patients operated for oropharyngeal cancer. In the postsurgical phase, two sequential energy levels were administered by nasogastric tube: (1) a 'maintenance' level (days 3-5) at 1.4 X measured presurgery BMR; (2) a 'supramaintenance' level (days 6-9) at 1.7 X measured BMR on day 6. Before surgery the patients had a BMR averaging (23.7 +/- 1.0 kcal/kg.day). After surgery BMR increased to 27.6 +/- 2.7 kcal/kg.day (day 6), then it decreased to 24.4 +/- 1.4 kcal/kg.day (day 10). The difference between RMR and BMR yielded a nutrient-induced thermogenesis averaging 5 +/- 1 and 8.5 +/- 2% (p less than 0.05) on levels 1 and 2, respectively. It is concluded that an energy level corresponding to 1.4 X presurgery BMR is sufficient to maintain energy and substrate equilibrium in nondepleted patients, whereas 1.7 X BMR induces positive protein and fat balances concomitant to a decrease efficiency of energy utilization.

[(18)F]FDG-PET Standard Uptake Value as a Metabolic Predictor of Bone Marrow Response to Radiation: Impact on Acute and Late Hematological Toxicity in Cervical Cancer Patients Treated With Chemoradiation Therapy.

PURPOSE: To quantify the relationship between bone marrow (BM) response to radiation and radiation dose by using (18)F-labeled fluorodeoxyglucose positron emission tomography [(18)F]FDG-PET standard uptake values (SUV) and to correlate these findings with hematological toxicity (HT) in cervical cancer (CC) patients treated with chemoradiation therapy (CRT). METHODS AND MATERIALS: Seventeen women with a diagnosis of CC were treated with standard doses of CRT. All patients underwent pre- and post-therapy [(18)F]FDG-PET/computed tomography (CT). Hemograms were obtained before and during treatment and 3 months after treatment and at last follow-up. Pelvic bone was autosegmented as total bone marrow (BMTOT). Active bone marrow (BMACT) was contoured based on SUV greater than the mean SUV of BMTOT. The volumes (V) of each region receiving 10, 20, 30, and 40 Gy (V10, V20, V30, and V40, respectively) were calculated. Metabolic volume histograms and voxel SUV map response graphs were created. Relative changes in SUV before and after therapy were calculated by separating SUV voxels into radiation therapy dose ranges of 5 Gy. The relationships among SUV decrease, radiation dose, and HT were investigated using multiple regression models. RESULTS: Mean relative pre-post-therapy SUV reductions in BMTOT and BMACT were 27% and 38%, respectively. BMACT volume was significantly reduced after treatment (from 651.5 to 231.6 cm(3), respectively; P<.0001). BMACT V30 was significantly correlated with a reduction in BMACT SUV (R(2), 0.14; P<.001). The reduction in BMACT SUV significantly correlated with reduction in white blood cells (WBCs) at 3 months post-treatment (R(2), 0.27; P=.04) and at last follow-up (R(2), 0.25; P=.04). Different dosimetric parameters of BMTOT and BMACT correlated with long-term hematological outcome. CONCLUSIONS: The volumes of BMTOT and BMACT that are exposed to even relatively low doses of radiation are associated with a decrease in WBC counts following CRT. The loss in proliferative BM SUV uptake translates into low WBC nadirs after treatment. These results suggest the potential of intensity modulated radiation therapy to spare BMTOT to reduce long-term hematological toxicity.

hMMP9 as predictive factor for response and progression free survival in breast cancer patients treated with bevacizumab and pegylated liposomal doxorubicin (PLD)

Background: The anti-angiogenic drug, bevacizumab (Bv), is currently used in the treatment of different malignancies including breast cancer. Many angiogenesis-associated molecules are found in the circulation of cancer patients. Until now, there are no prognostic or predictive factors identified in breast cancer patients treated with Bv. We present here the first results of the prospective monitoring of 6 angiogenesis-related molecules in the peripheral blood of breast cancer patients treated with a combination of Bv and PLD in the phase II trial, SAKK 24/06. Methods: Patients were treated with PLD (20 mg/m2) and Bv (10 mg/kg) on days 1 and 15 of each 4-week cycle for a maximum of 6 cycles, followed by Bv monotherapy maintenance (10 mg/m2 q2 weeks) until progression or severe toxicity. Plasma and serum samples were collected at baseline, after 2 months of therapy, then every 3 months and at treatment discontinuation. Enzyme-linked immunosorbent assays (Quantikine, R&D Systems and Reliatech) were used to measure the expression levels of human vascular endothelial growth factor (hVEGF), placental growth factor (hPlGF), matrix metalloproteinase 9 (hMMP9) and soluble VEGF receptors hsVEGFR-1, hsVEGFR-2 and hsVEGFR-3. The log-transformed data (to reduce the skewness) for each marker was analyzed using an analysis of variance (ANOVA) model to determine if there was a difference between the mean of the subgroups of interest (where α = 0.05). The untransformed data was also analyzed in the same manner as a "sensitivity" check. Results: 132 blood samples were collected in 41 out of 43 enrolled patients. Baseline levels of the molecules were compared to disease status according to RECIST. There was a statistically significant difference in the mean of the log-transformed levels of hMMP9 between responders [CR+PR] versus the mean in patients with PD (p-value=0.0004, log fold change=0.7536), and between patients with disease control [CR+PR+SD] and those with PD (p-value=<0.0001, log fold change=0.81559), with the log-transformed level of hMMP9 being higher for the responder group. The mean of the log-transformed levels of hsVEGFR-1 was statistically significantly different between patients with disease control [CR+PR+SD] and those with PD (p-value=0.0068, log fold change=-0.6089), where the log-transformed level of hsVEGFR-1 was lower for the responder group. The log-transformed level of hMMP9 at baseline was identified as a significant prognostic factor in terms of progression free survival (PFS): p-value=0.0417, hazard ratio (HR)=0.574 with a corresponding 95% confidence interval (0.336 - 0.979)). No strong correlation was shown either between the log-transformed levels of hsVEGF, hPlGF, hsVEGFR-2 or hsVEGFR-3 and clinical response or the occurrence of severe toxicity, or between the levels of the different molecules. Conclusions: Our results suggest that baseline plasma level of the matrix metalloproteinase, hMMP9, could predict tumor response and PFS in patients treated with a combination of Bv and PLD. These data justify further investigation in breast cancer patients treated with anti-angiogenic therapy.

The role of PET/CT in cervical cancer.

In locally advanced cervical cancer, (18)F-fluorodeoxyglucose (FDG) positron emission tomography - computed tomography (PET/CT) has become important in the initial evaluation of disease extent. It is superior to other imaging modalities for lymph node status and distant metastasis. PET-defined cervical tumor volume predicts progression-free and overall survival. Higher FDG uptake in both primary and regional lymph nodes is strongly predictive of worse outcome. FDG-PET is useful for assessing treatment response 3 months after completing concurrent chemo-radiotherapy (CRT) and predicting long-term survival, and in suspected disease recurrence. In the era of image-guided adaptive radiotherapy, accurately defining disease areas is critical to avoid irradiating normal tissue. Based on additional information provided by FDG-PET, radiation treatment volumes can be modified and higher doses to FDG-positive lymph nodes safely delivered. FDG-PET/CT has been used for image-guided brachytherapy of FDG-avid tumor volume, while respecting low doses to bladder and rectum. Despite survival improvements due to CRT in cervical cancer, disease recurrences continue to be a major problem. Biological rationale exists for combining novel non-cytotoxic agents with CRT, and drugs targeting specific molecular pathways are under clinical development. The integration of these targeted therapies in clinical trials, and the need for accurate predictors of radio-curability is essential. New molecular imaging tracers may help identifying more aggressive tumors. (64)Cu-labeled diacetyl-di(N(4)-methylthiosemicarbazone) is taken up by hypoxic tissues, which may be valuable for prognostication and radiation treatment planning. PET/CT imaging with novel radiopharmaceuticals could further impact cervical cancer treatment as surrogate markers of drug activity at the tumor microenvironment level. The present article reviews the current and emerging role of PET/CT in the management of cervical cancer.

Mutations of mitochondrial DNA as potential biomarkers in breast cancer.

BACKGROUND: Alterations of mitochondrial DNA (mtDNA) have been found in cancer patients, therefore informative mtDNA mutations could serve as biomarkers for the disease. MATERIALS AND METHODS: The two hypervariable regions HVR1 and HVR2 in the D-Loop region were sequenced in ten paired tissue and plasma samples from breast cancer patients. RESULTS: MtDNA mutations were found in all patients' samples, suggesting a 100% detection rate. Examining germline mtDNA mutations, a total of 85 mutations in the D-loop region were found; 31 of these mutations were detected in both tissues and matched plasma samples, the other 54 germline mtDNA mutations were found only in the plasma samples. Regarding somatic mtDNA mutations, a total of 42 mutations in the D-loop region were found in breast cancer tissues. CONCLUSION: Somatic mtDNA mutations in the D-loop region were detected in breast cancer tissues but not in the matched plasma samples, suggesting that more sensitive methods will be needed for such detection to be of clinical utility.

Antitumor activities of ATP-competitive inhibitors of mTOR in colon cancer cells

Le cancer colorectal est la 3ème cause de décès liée au cancer dans l'Europe de l'Ouest et nécessite une prise en charge pluridisciplinaire. Les thérapies anticancéreuses récentes développées visent à inhiber les voies de signalisation cellulaires responsables de la prolifération des cellules tumorales. L'inhibition de la voie de signalisation cellulaire mTOR, est une stratégie prometteuse. En effet, mTOR est souvent suractivé dans les cellules du cancer colorectal et régule la croissance, la prolifération et la survie cellulaire. De nombreuses études récentes ont démontrés l'importance de l'activité de mTOR dans le développement du cancer colorectal et l'efficacité anti-tumorale des inhibiteurs allostériques de mTOR, telle que la rapamycine. Récemment, une nouvelle classe d'inhibiteur de mTOR, notamment PP242 et NVP-BEZ235, agissant comme inhibiteur ATP- compétitif a été développée. L'efficacité de ces inhibiteurs n'a pas été démontrée dans le contexte du cancer colorectal. Dans cette étude, nous avons comparé l'effet de PP242, un inhibiteur ATP-compétitif de mTOR et NVP-BEZ235, un inhibiteur dual de PI3K/mTOR par rapport à la rapamycine. Nous avons étudié, in vitro, leur effet sur la croissance, la prolifération et la survie cellulaire sur des lignées cellulaires du cancer du colon (LS174, SW480 et DLD-1) et, in vivo, sur la croissance de xénogreffes dans un modèle murin. Nous avons émis l'hypothèse que l'effet des ces nouveaux inhibiteurs seraient plus importants qu'avec la rapamycine. Nous avons observé que le PP242 et le NVP-BEZ235 réduisent significativement et de façon plus marquée que la rapamycine la croissance, la prolifération et la survie cellulaire des cellules LS174T et DLD-1. Ces inhibiteurs réduisent également la prolifération et la survie cellulaire des cellules SW480 alors que celles-ci étaient résistantes à la rapamycine. Nous avons également observé que les inhibiteurs PP242 et NVP-BEZ235 réduisaient la croissance des xénogreffes avec les lignées cellulaires LS174 et SW480. Finalement, nous avons remarqué que l'effet anti-tumoral des inhibiteurs ATP-compétitifs de mTOR était potentialisé par l'U0126, un inhibiteur de MEK/MAPK, souvent activé dans les voies de signalisation cellulaire du cancer colorectal. En conclusion, nous avons observé que les inhibiteurs ATP-compétitifs de mTOR bloquent la croissance de cellules tumorales du cancer colorectal in vitro et in vivo. Ces résultats démontrent que ces inhibiteurs représentent une option thérapeutique prometteuse dans le traitement du cancer colorectal et méritent d'être évalués dans des études cliniques.

An ultra-sensitive impedimetric immunosensor for detection of the serum oncomarker CA-125 in ovarian cancer patients.

Effective treatment of ovarian cancer depends upon the early detection of the malignancy. Here, we report on the development of a new nanostructured immunosensor for early detection of cancer antigen 125 (CA-125). A gold electrode was modified with mercaptopropionic acid (MPA), and then consecutively conjugated with silica coated gold nanoparticles (AuNP@SiO2), CdSe quantum dots (QDs) and anti-CA-125 monoclonal antibody (mAb). The engineered MPA|AuNP@SiO2|QD|mAb immunosensor was characterised using transmission electron microscopy (TEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Successive conjugation of AuNP@SiO2, CdSe QD and anti-CA-125 mAb onto the gold electrode resulted in sensitive detection of CA-125 with a limit of detection (LOD) of 0.0016 U mL(-1) and a linear detection range (LDR) of 0-0.1 U mL(-1). Based on the high sensitivity and specificity of the immunosensor, we propose this highly stable and reproducible biosensor for the early detection of CA-125.

Retrospective feasibility study of simultaneous integrated boost in cervical cancer using Tomotherapy: the impact of organ motion and tumor regression.

BACKGROUND: Whole pelvis intensity modulated radiotherapy (IMRT) is increasingly being used to treat cervical cancer aiming to reduce side effects. Encouraged by this, some groups have proposed the use of simultaneous integrated boost (SIB) to target the tumor, either to get a higher tumoricidal effect or to replace brachytherapy. Nevertheless, physiological organ movement and rapid tumor regression throughout treatment might substantially reduce any benefit of this approach. PURPOSE: To evaluate the clinical target volume - simultaneous integrated boost (CTV-SIB) regression and motion during chemo-radiotherapy (CRT) for cervical cancer, and to monitor treatment progress dosimetrically and volumetrically to ensure treatment goals are met. METHODS AND MATERIALS: Ten patients treated with standard doses of CRT and brachytherapy were retrospectively re-planned using a helical Tomotherapy - SIB technique for the hypothetical scenario of this feasibility study. Target and organs at risk (OAR) were contoured on deformable fused planning-computed tomography and megavoltage computed tomography images. The CTV-SIB volume regression was determined. The center of mass (CM) was used to evaluate the degree of motion. The Dice's similarity coefficient (DSC) was used to assess the spatial overlap of CTV-SIBs between scans. A cumulative dose-volume histogram modeled estimated delivered doses. RESULTS: The CTV-SIB relative reduction was between 31 and 70%. The mean maximum CM change was 12.5, 9, and 3 mm in the superior-inferior, antero-posterior, and right-left dimensions, respectively. The CTV-SIB-DSC approached 1 in the first week of treatment, indicating almost perfect overlap. CTV-SIB-DSC regressed linearly during therapy, and by the end of treatment was 0.5, indicating 50% discordance. Two patients received less than 95% of the prescribed dose. Much higher doses to the OAR were observed. A multiple regression analysis showed a significant interaction between CTV-SIB reduction and OAR dose increase. CONCLUSIONS: The CTV-SIB had important regression and motion during CRT, receiving lower therapeutic doses than expected. The OAR had unpredictable shifts and received higher doses. The use of SIB without frequent adaptation of the treatment plan exposes cervical cancer patients to an unpredictable risk of under-dosing the target and/or overdosing adjacent critical structures. In that scenario, brachytherapy continues to be the gold standard approach.

Worldwide trends in gastric cancer mortality (1980-2011), with predictions to 2015, and incidence by subtype.

Gastric cancer incidence and mortality decreased substantially over the last decades in most countries worldwide, with differences in the trends and distribution of the main topographies across regions. To monitor recent mortality trends (1980-2011) and to compute short-term predictions (2015) of gastric cancer mortality in selected countries worldwide, we analysed mortality data provided by the World Health Organization. We also analysed incidence of cardia and non-cardia cancers using data from Cancer Incidence in Five Continents (2003-2007). The joinpoint regression over the most recent calendar periods gave estimated annual percent changes (EAPC) around -3% for the European Union (EU) and major European countries, as well as in Japan and Korea, and around -2% in North America and major Latin American countries. In the United States of America (USA), EU and other major countries worldwide, the EAPC, however, were lower than in previous years. The predictions for 2015 show that a levelling off of rates is expected in the USA and a few other countries. The relative contribution of cardia and non-cardia gastric cancers to the overall number of cases varies widely, with a generally higher proportion of cardia cancers in countries with lower gastric cancer incidence and mortality rates (e.g. the USA, Canada and Denmark). Despite the favourable mortality trends worldwide, in some countries the declines are becoming less marked. There still is the need to control Helicobacter pylori infection and other risk factors, as well as to improve diagnosis and management, to further reduce the burden of gastric cancer.

Intraoperative training on the techniques of sentinel node biopsy in breast cancer

Principles: Surgeon's experience is crucial for proper application of sentinel node biopsy (SNB) in patients with breast cancer. A 20-30 cases learning curve of sentinel node (SN) and axillary lymph node dissection (ALND) was widely practiced. In order to speed up this learning curve, surgeons may be trained intraoperative by an experienced surgeon. The purpose of this report is to evaluate the results of this procedure. Methods: Patients with one primary invasive breast cancer (cT1-T2[<3 cm]cN0) underwent SNB based on lymphoscintigraphy using technetium Tc 99m colloid, intraoperative gamma probe detection, with or without blue dye mapping. This was followed by completion ALND when SN was positive or not found. SNB was performed by one experienced surgeon (teacher) or by 10 junior surgeons trained by the experienced surgeon (trainees). Four groups were defined: (i) SNB with immediate ALND for the teacher's learning curve, (ii) SNB by the teacher, (iii) SNB by the trainees under the teacher's supervision, and (iv) SNB by the trainees alone. Results: Between May 1999 and December 2007, a total of 808 évaluable patients underwent SNB. The SN identification rate was 98% in the teacher's group, and 99% in the trainees' group (p = 0.196). SN were positive in respectively 28% and 29% of patients (p = 0.196). The distribution of isolated tumor cells, micrometastases and metastases was not statistically different between the teacher's and the trainees' groups (p = 0.163). Conclusion: These comparable results confirm the success with which the SNB was taught. This strategy avoided the 20-30 SNB followed by immediate ALND early required per surgeon.

Empirical antifungal therapy in neutropaenic cancer patients with persistent fever

Invasive fungal infections are frequent and severe complications in leukaemic patients with prolonged neutropaenia. Empirical antifungal therapy has become the standard of care in patients with persistent fever despite treatment with broad-spectrum antibiotics. For decades amphotericin B deoxycholate has been the sole option for empirical antifungal therapy. Recently, several new antifungal agents became available. The choice of the most appropriate drug should be guided by efficacy and safety criteria. The recommendations from the First European Conference on Infections in Leukaemia (ECIL-1) on empirical antifungal therapy in neutropaenic cancer patients with persistent fever have been developed by an expert panel after assessment of clinical practices in Europe and evidence-based review of the literature. Many antifungal regimens can now be recommended for empirical therapy in neutropaenic cancer patients. However, persistent fever lacks specificity for initiation of therapy. Development of empirical and pre-emptive strategies using new clinical parameters, laboratory markers and imaging techniques for early diagnosis of invasive mycoses are needed.

CPT-11 and concomitant hyperfractionated accelerated radiotherapy induce efficient local control in rectal cancer patients: results from a phase II.

Patients with rectal cancer are at high risk of disease recurrence despite neoadjuvant radiochemotherapy with 5-Fluorouracil (5FU), a regimen that is now widely applied. In order to develop a regimen with increased antitumour activity, we previously established the recommended dose of neoadjuvant CPT-11 (three times weekly 90 mg m(-2)) concomitant to hyperfractionated accelerated radiotherapy (HART) followed by surgery within 1 week. Thirty-three patients (20 men) with a locally advanced adenocarcinoma of the rectum were enrolled in this prospective phase II trial (1 cT2, 29 cT3, 3 cT4 and 21 cN+). Median age was 60 years (range 43-75 years). All patients received all three injections of CPT-11 and all but two patients completed radiotherapy as planned. Surgery with total mesorectal excision (TME) was performed within 1 week (range 2-15 days). The preoperative chemoradiotherapy was overall well tolerated, 24% of the patients experienced grade 3 diarrhoea that was easily manageable. At a median follow-up of 2 years no local recurrence occurred, however, nine patients developed distant metastases. The 2-year disease-free survival was 66% (95% confidence interval 0.48-0.83). Neoadjuvant CPT-11 and HART allow for excellent local control; however, distant relapse remains a concern in this patient population.

The biology of cancer stem cells : part 1: nuclear translocation of CD44 : part 2: IMP2 in glioblastoma cancer stem cells

SummaryCancer stem cells (CSC) are poorly differentiated, slowly proliferating cells, with high tumorigenic potential. Some of these cells, as it has been shown in leukemia, evade chemo- and radiotherapy and recapitulate the tumor composed of CSC and their highly proliferative progeny. Therefore, understanding the molecular biology of those cells is crucial for improvement of currently used anti-cancer therapies.This work is composed of two CSC-related projects. The first deals with CD44, a frequently used marker of CSC; the second involves Imp2 and its role in CSC bioenergetics. PART 1. CD44 is a multifunctional transmembrane protein involved in migration, homing, adhesion, proliferation and survival. It is overexpressed in many cancers and its levels are correlated with poor prognosis. CD44 is also highly expressed by CSC and in many malignancies it is used for CSC isolation.In the present work full-lenght CD44 nuclear localization was studied, including the mechanism of nuclear translocation and its functional role in the nucleus. Full-length CD44 can be found in nuclei of various cell types, regardless of their tumorigenic potential. For nuclear localization, CD44 needs to be first inserted into the cell membrane, from which it is transported via the endocytic pathway. Upon binding to transportinl it is translocated to the nucleus. The nuclear localization signal recognized by transportinl has been determined as the first 20 amino acids of the membrane proximal intracellular domain. Nuclear export of CD44 is facilitated by exportin Crml. Investigation of the function of nuclear CD44 revealed its implication in de novo RNA synthesis.PART 2. Glioblastoma multiforme is the most aggressive and most frequent brain malignancy. It was one of the first solid tumors from which CSC have been isolated. Based on the similarity between GBM CSC and normal stem cells expression of an oncofetal mRNA binding protein Imp2 has been investigated.Imp2 is absent in normal brain as well as in low grade gliomas, but is expressed in over 75% GBM cases and its expression is higher in CSC compared to their more differentiated counterparts. Analysis of mRNA transcripts bound by Imp2 and its protein interactors revealed that in GBM CSC Imp2 may be implicated in mitochondrial metabolism. Indeed, shRNA mediated silencing of protein expression led to decreased mitochondrial activity, decreased oxygen consumption and decreased activity of respiratory chain protein complex I. Moreover, lack of Imp2 severely affected self-renewal and tumorigenicity of GBM CSC. Experimental evidence suggest that GBM CSC depend on mitochondrial oxidative phosphorylation as an energy producing pathway and that Imp2 is a novel regulator of this pathway.RésuméLes cellules cancéreuses souches sont des cellules peu différentiées, à proliferation lente et hautement tumorigénique. Ces cellules sont radio-chimio résistantes et sont capable reformer la tumeur dans sont intégralité, reproduisant l'hétérogénéité cellulaire présent dans la tumeur d'origine. Pour améliorer les therapies antitumorales actuelles il est crucial de comprendre les mécanismes moléculaires qui caractérisent cette sous-population de cellules hautement malignes.Ce travail de thèse se compose de deux projets s'articulant autour du même axe :Le CD44 est une protéine multifonctionnelle et transmembranaire très souvent utilisée comme marqueur de cellules souches tumorales dans différents cancers. Elle est impliquée dans la migration, l'adhésion, la prolifération et la survie des cellules. Lors de ce travail de recherche, nous nous sommes intéressés à la localisation cellulaire du CD44, ainsi qu'aux mécanismes permettant sa translocation nucléaire. En effet, bien que principalement décrit comme un récepteur de surface transmembranaire, le CD44 sous sa forme entière, non clivée en peptides, peut également être observé à l'intérieur du noyau de diverses cellules, quel que soit leur potentiel tumorigénique. Pour passer ainsi d'un compartiment cellulaire à un autre, le CD44 doit d'abord être inséré dans la membrane plasmique, d'où il est transporté par endocytose jusqu'à l'intérieur du cytoplasme. La transportai permet ensuite la translocation nucléaire du CD44 via une « séquence signal » contenue dans les 20 acides aminés du domaine cytoplasmique qui bordent la membrane. A l'inverse, le CD44 est exporté du noyau grâce à l'exportin Crml. En plus des mécanismes décrits ci-dessus, cette étude a également mis en évidence l'implication du CD44 dans la synthèse des ARN, d'où sa présence dans le noyau.Le glioblastome est la plus maligne et la plus fréquente des tumeurs cérébrales. Dans ce second projet de recherche, le rôle de IMP2 dans les cellules souches tumorales de glioblastomes a été étudié. La présence de cette protéine oncofoetale a d'abord été mise en évidence dans 75% des cas les plus agressifs des gliomes (grade IV, appelés glioblastomes), tandis qu'elle n'est pas exprimée dans les grades I à III de ces tumeurs, ni dans le cerveau sain. De plus, IMP2 est apparue comme étant davantage exprimée dans les cellules souches tumorales que dans les cellules déjà différenciées. La baisse de l'expression de IMP2 au moyen de shRNA a résulté en une diminution de l'activité mitochondriale, en une réduction de la consommation d'oxygène ainsi qu'en une baisse de l'activité du complexe respiratoire I.L'inhibition de IMP2 a également affecté la capacité de renouvellement de la population des cellules souches tumorales ainsi que leur aptitude à former des tumeurs.Lors de ce travail de thèse, une nouvelle fonction d'un marqueur de cellules souches tumorales a été mise en évidence, ainsi qu'un lien important entre la bioénergétique de ces cellules et l'expression d'une protéine oncofoetale.

Minimal clinically meaningful differences for the EORTC QLQ-C30 and EORTC QLQ-BN20 scales in brain cancer patients.

BACKGROUND: We aimed to determine the smallest changes in health-related quality of life (HRQoL) scores in the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire core 30 and the Brain Cancer Module (QLQ-BN20), which could be considered as clinically meaningful in brain cancer patients. Materials and methods: World Health Organisation performance status (PS) and mini-mental state examination (MMSE) were used as clinical anchors appropriate to related subscales to determine the minimal clinically important differences (MCIDs) in HRQoL change scores (range 0-100) in the QLQ-C30 and QLQ-BN20. A threshold of 0.2 standard deviation (SD) (small effect) was used to exclude anchor-based MCID estimates considered too small to inform interpretation. RESULTS: Based on PS, our findings support the following integer estimates of the MCID for improvement and deterioration, respectively: physical (6, 9), role (14, 12), and cognitive functioning (8, 8); global health status (7, 4*), fatigue (12, 9), and motor dysfunction (4*, 5). Anchoring with MMSE, cognitive functioning MCID estimates for improvement and deterioration were (11, 2*) and for communication deficit were (9, 7). Estimates with asterisks were <0.2 SD and were excluded from our MCID range of 5-14. CONCLUSION: These estimates can help clinicians evaluate changes in HRQoL over time, assess the value of a health care intervention and can be useful in determining sample sizes in designing future clinical trials.