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A Couvelard

Publications and source records attributed to A Couvelard.

At least 19 recordsLinked to original sources
PubMed2006

Arterial phase enhancement and body mass index are predictors of response to chemoembolisation for liver metastases of endocrine tumours.

Transcatheter arterial chemoembolisation (TACE) has been reported to be an efficient treatment of liver metastases of endocrine tumours in short series of patients. However, several factors seem to affect its results. The aim of this work is to identify predictors of response to TACE for liver metastases of endocrine tumours. A total of 163 TACE procedures were performed in 67 patients between 1994 and 2004. Forty-four patients were treated with streptozotocin and 23 with doxorubicin. Primary tumour was located in the pancreas for 19 patients, and had been removed in 43. Thirty-eight tumours were functioning. Response rate was 37% (confidence interval [CI] 95%: 28-49%). Median time to progression (TTP) was 14.5 months (CI 95%: 9-41). In multivariate analysis (n=43), predictors of tumour response were body mass index (BMI) (odds ratio [OR]: 1.3; CI 95%: 1.04-1.63; P=0.022), functioning type of tumour (OR: 7.31; CI 95%: 1.26-42.5; P=0.027), arterial phase enhancement on abdominal computed tomography (CT) (OR: 8.11; CI 95%:1.06-62; P=0.044) and use of streptozotocin for cytotoxic agent (OR: 21.3; CI 95%: 1.48-306; P=0.025). Analysis of TTP predictors showed that BMI (hazard ratio [HR]: 0.85; CI 95%: 0.76-0.86; P=0.01) and arterial phase enhancement (HR: 0.3; CI 95%: 0.12-0.73; P=0.008) were associated with delayed progression. This large study confirms the previously reported results of TACE regarding its efficacy for the treatment of liver metastases of endocrine tumours. Arterial phase enhancement on abdominal CT and BMI are predictors of treatment's efficacy. Streptozotocin should be the preferred cytotoxic agent in order to save anthracycline for systemic chemotherapy.

Adult↗
PubMed2006

TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system.

The need for standards in the management of patients with endocrine tumors of the digestive system prompted the European Neuroendocrine Tumor Society (ENETS) to organize a first Consensus Conference, which was held in Frascati (Rome) and was based on the recently published ENETS guidelines on the diagnosis and treatment of digestive neuroendocrine tumors (NET). Here, we report the tumor-node-metastasis proposal for foregut NETs of the stomach, duodenum, and pancreas that was designed, discussed, and consensually approved at this conference. In addition, we report the proposal for a working formulation for the grading of digestive NETs based on mitotic count and Ki-67 index. This proposal, which needs to be validated, is meant to help clinicians in the stratification, treatment, and follow-up of patients.

Biomarkers, Tumor↗
PubMed2006

Human pancreatic mucinous cystadenoma is characterized by distinct mucin, cytokeratin and CD10 expression compared with intraductal papillary-mucinous adenoma.

AIMS: To examine cytokeratin, epithelial glycoprotein (mucin) and glycoprotein CD10 expression in benign mucinous cystdenomas (MCAs) in comparison with intraductal papillary mucinous adenomas (IPMAs). METHODS AND RESULTS: Thirty MCAs of the pancreas were analysed for immunohistochemical expression of cytokeratin (CK) 7, CK20, MUC1, MUC2, MUC5AC and CD10 and were compared with 16 IPMAs. CK7 was expressed in all neoplasms. CK20 was significantly more frequent in MCAs compared with IPMAs (56.66% versus 18.75%, P = 0.027). MUC1 was more frequent in MCAs (40% versus 12.5%, P = 0.0915), whereas MUC5AC was significantly less frequent in MCAs (33.33% versus 100%). MUC2 was expressed in goblet cells of seven MCAs. In MCAs, CD10 was observed both in epithelial cells and in the ovarian-type stromal cells (24/30). Epithelial expression of CD10 was significantly lower in IPMAs (66.66% versus 6.25%, p = 0.0001). CONCLUSIONS: MCA is characterized by a significantly greater frequency of expression of CK20 and CD10 when compared with IPMA, which preferentially expresses MUC5AC.

Adolescent↗
PubMed2006

[Non transplant-related constrictive bronchiolitis in adults].

INTRODUCTION: The term bronchiolitis refers to inflammatory disorders of the bronchioles. Constrictive bronchiolitis is the type most frequently encountered. STATE OF THE ART/PERSPECTIVES: The main clinical manifestations include the development of exertional dyspnoea and fixed airflow obstruction. Chest x-ray findings are usually unhelpful, but CT scanning may reveal a mosaic pattern on expiration. Peripheral micronodules are less frequently seen. The causes of constrictive bronchiolitis are numerous. The diagnosis may be clear from the clinical context when a causative event or predisposing condition can be identified (lung or bone marrow transplantation, toxic fume or gas inhalation, rheumatoid arthritis); in other conditions, a stepwise approach to the diagnosis is usually recommended in order to exclude other causes of subacute or chronic obstructive disease. Formal diagnosis requires histological examination of surgical lung biopsies. Despite corticosteroid administration, respiratory failure usually develops. Specific inhibitors of pro-inflammatory cytokines may offer a new and promising therapeutic approach. CONCLUSIONS: If the clinical context or the radiology and clinical findings are not highly suggestive of a constrictive bronchiolitis, a surgical lung biopsy should be considered.

Adult↗
PubMed2005

Endocrine pancreatic tumours and helical CT: contrast enhancement is correlated with microvascular density, histoprognostic factors and survival.

PURPOSE: To assess the role of contrast-enhanced helical CT in the evaluation of tumour vascularity in endocrine pancreatic tumours (EPTs), and to determine the predictive factors of malignancy of EPTs at helical CT with CT-histopathological correlation. MATERIALS AND METHODS: Thirty-seven consecutive patients with histopathologically proven EPTs underwent dual-phase helical CT. For each tumour detected, its density relative to the surrounding parenchyma was scored on the pancreatic phase using a 5-point scale. Radiological findings were correlated with histopathological (vessel density count) and clinical follow-up findings. RESULTS: Thirty of 37 patients had non-functioning EPTs and overall 44 tumours were detected by helical CT (mean size 38, range 5-100 mm). CT showed calcifications in 10 tumours. Calcifications were associated with well-differentiated carcinomas (90%, p = 0.02). Vascular density assessed by light microscopy was significantly correlated with tumour enhancement at the pancreatic phase (p = 0.0001). Poorly differentiated carcinomas were less vascularised than well-differentiated tumours and carcinomas (34 vs. 264 vessels/mm2, p = 0.0073). Tumour differentiation also correlated with tumour enhancement at the pancreatic phase (p = 0.0044, trend test): poorly differentiated carcinomas were hypoattenuating (71%) and isoattenuating or weakly hyperattenuating (29%), compared with well-differentiated carcinomas and tumours that were mainly moderately or strongly hyperattenuating (53%). In univariate analysis, poor tumoral differentiation, hepatic metastasis, high mitotic index, poor tumoral enhancement at the pancreatic phase and less vascularised tumours were correlated with decreased survival rate. CONCLUSION: Enhancement of EPT at CT is correlated with tumour vascularity assessed by light microscopy. Low-enhancing EPT at CT are correlated with poorly differentiated EPT and with a decrease in overall survival.

Adult↗
PubMed2005

Microvascular density and hypoxia-inducible factor pathway in pancreatic endocrine tumours: negative correlation of microvascular density and VEGF expression with tumour progression.

Tumour-associated angiogenesis is partly regulated by the hypoxia-inducible factor (HIF) pathway. Endocrine tumours are highly vascularised and the molecular mechanisms of their angiogenesis are not fully delineated. The aim of this study is to evaluate angiogenesis and expression of HIF-related molecules in a series of patients with pancreatic endocrine tumours (PETs). The expression of vascular endothelial growth factor (VEGF), HIF-1alpha, HIF-2alpha and carbonic anhydrase 9 (CA9) was examined by immunohistochemistry in 45 patients with PETs and compared to microvascular density (MVD), endothelial proliferation, tumour stage and survival. Microvascular density was very high in PETs and associated with a low endothelial index of proliferation. Microvascular density was significantly higher in benign PETs than in PETs of uncertain prognosis, well-differentiated and poorly differentiated carcinomas (mean values: 535, 436, 252 and 45 vessels mm(-2), respectively, P < 0.0001). Well-differentiated tumours had high cytoplasmic VEGF and HIF-1alpha expression. Poorly differentiated carcinomas were associated with nuclear HIF-1alpha and membranous CA9 expression. Low MVD (P = 0.0001) and membranous CA9 expression (P = 0.0004) were associated with a poorer survival. Contrary to other types of cancer, PETs are highly vascularised, but poorly angiogenic tumours. As they progress, VEGF expression is lost and MVD significantly decreases. The regulation of HIF signalling appears to be specific in pancreatic endocrine tumours.

Adenoma, Islet Cell↗
PubMed2005

Primary endocrine tumours of the liver.

BACKGROUND: In patients with hepatic endocrine tumours, a primary neoplasm is not always found elsewhere despite extensive investigations, raising the possibility that the hepatic lesion is the primary tumour. The aim of this study was to assess the incidence, characteristics and prognosis of patients with primary hepatic endocrine tumours. METHODS: Patients with histologically confirmed hepatic endocrine tumours identified since 1993 were reviewed. All those with no primary tumour identified by computed tomography of the thorax, abdomen and pelvis, upper and lower digestive endoscopy, duodenopancreatic endoscopic ultrasonography or somatostatin receptor scintigraphy (SRS) were included. Clinical and tumour characteristics were assessed retrospectively. RESULTS: Of 393 patients with digestive endocrine tumours, 17 (seven men; median age 55 (range 26-69) years) had hepatic endocrine tumours without evidence of an extrahepatic primary lesion either at diagnosis or during a median follow-up of 43 (range 12-108) months. Ten patients had multiple and seven had single tumours. The tumours were non-functional in 13 patients and well differentiated in 14 patients. SRS was positive in the liver in 11 patients. Curative resection was performed in seven. Overall actuarial survival rates were 100, 69 and 51 per cent at 1, 3 and 5 years respectively. Only poor differentiation was associated with an unfavourable outcome (relative risk 20.8; P < 0.001). CONCLUSION: Primary hepatic endocrine tumours were identified in almost 5 per cent of patients with digestive endocrine tumours. Poor differentiation was the only factor associated with unfavourable outcome.

Adult↗
PubMed2005

[Intraductal papillary mucinous tumours of the pancreas: imaging features].

IPMTP is a pancreatic duct disease that can better be diagnosed due to advances in imaging techniques. This probably explains the recent increased frequency of this disease. Enlargement of the main pancreatic duct and/or branch ducts is a typical feature. CT and MRI with MRCP are useful for diagnosis. Features of malignant degeneration are better known. Preoperative staging is performed at CT. Differential diagnosis includes main pancreatic duct dilatation and pancreatic cysts. Recent papers indicate that isolated side branch IPMTP is less frequently malignant. Surgery is indicated in the presence of acute pancreatitis or suspicion of malignant degeneration. Imaging is useful for the follow up of patients with isolated side branch IPMTP. In this paper, the diagnostic, staging and malignant features of IPMTP will be reviewed.

Carcinoma, Pancreatic Ductal↗
PubMed2005

Expression of hypoxia-inducible factors is correlated with the presence of a fibrotic focus and angiogenesis in pancreatic ductal adenocarcinomas.

AIMS: To study the expression of hypoxia-regulated markers in pancreatic ductal adenocarcinomas (PA) in relationship to the presence of a fibrotic focus, angiogenesis quantification and clinical outcome. METHODS AND RESULTS: The expression of hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, carbonic anhydrase 9 (CA9) and vascular endothelial growth factor (VEGF) was immunohistochemically detected in 50 PA and correlated with tumour characteristics, microvascular density (MVD) and survival. HIF-1alpha was expressed within tumour cells in 68%, HIF-2alpha in 46%, CA9 in 78% and VEGF in 52% of the cases. Stromal expression was also noted for HIF-2alpha and CA9 in, respectively, 42% and 48% of the cases. Tumour CA9 expression was associated with that of VEGF (P=0.004) and that of stromal HIF-2alpha (P=0.013), with the presence of a fibrotic focus (P=0.046) and with an increased MVD (P=0.034). Tumour VEGF expression correlated with the presence of a fibrotic focus (P=0.039) and a greater MVD (P=0.047). Both the presence of a fibrotic focus (P=0.0002) and high tumour CA9 expression (P=0.029) were associated with reduced overall survival. CONCLUSION: The strong association of the presence of a fibrotic focus with CA9 expression and lower survival demonstrates that hypoxia-driven angiogenesis plays an important role in the progression of PA.

Adult↗
PubMed2004

Angiogenesis and extracellular matrix remodelling in bronchioloalveolar carcinomas: distinctive patterns in mucinous and non-mucinous tumours.

AIM: Bronchioloalveolar carcinomas (BACs) are rare primitive lung adenocarcinomas growing along the alveolar septum without stromal, vascular or pleural invasion. We report an immunohistochemical study of their vascular microenvironment. METHODS AND RESULTS: In three mucinous BACs (M-BAC) and three non-mucinous BACs (NM-BAC) we examined the following parameters in comparison with the normal lung: (i) constituents of the alveolar extracellular matrix; (ii) qualitative and quantitative changes of alveolar capillaries; and (iii) expression of vascular endothelial growth factor (VEGF) by tumour cells. In M-BAC, the alveolar matrix was unchanged compared with the normal parenchyma. Capillaries expressed normal alveolar endothelial markers and their average surface was calculated, as in normal lung, as 8%. VEGF was negative in tumour cells. In NM-BAC, the alveolar wall was thickened by deposits of fibronectin and type III collagen containing myofibroblasts and the basement membrane was disrupted. Capillaries did not retain alveolar endothelial markers and their surface was calculated as 19%. Tumour cells expressed high levels of VEGF. CONCLUSIONS: In contrast to NM-BAC, M-BAC do not modify the alveolar structure and seem to exploit the normal alveolar vascular bed to grow, without inducing neoangiogenesis. A better understanding of the mechanisms of growth of lung cancers may have implications for future anti-angiogenic therapeutic strategies.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2003

Cyclooxygenase-2 is expressed frequently and early in Barrett's oesophagus and associated adenocarcinoma.

AIMS: To establish the prevalence of cyclooxygenase-2 (COX-2) expression in a large series of resected Barrett's adenocarcinoma and associated preneoplastic lesions and to correlate this expression with clinicopathological data and prognosis. METHODS: COX-2 expression was assessed by immunohistochemistry in resected surgical specimens of 66 Barrett's adenocarcinomas and 32 cases of Barrett's mucosa (with dysplasia in 17 cases). RESULTS: Epithelial expression of COX-2 protein was increased in Barrett's mucosa compared with normal oesophagus. Epithelial expression of COX-2 was found in 91% of Barrett's specialized mucosa negative for dysplasia, 94% of Barrett's mucosa with dysplasia, and 97% of Barrett's adenocarcinoma. COX-2 expression was significantly higher in the well-differentiated adenocarcinomas when compared with the poorly differentiated tumours. There was no significant correlation between COX-2 expression and the other pathological features of the tumours. Survival analysis showed no significant prognostic value for COX-2. CONCLUSION: Our results confirm up-regulation of COX-2 in Barrett's oesophagus-metaplastic and dysplastic-and in Barrett's adenocarcinoma. Increased COX-2 expression did not differ during the progression from Barrett's oesophagus negative for dysplasia to Barrett's adenocarcinoma and is related to adenocarcinoma whose histology is well differentiated. This suggests that enhanced expression of COX-2 may occur early during Barrett's-associated neoplastic transformation.

Adenocarcinoma↗
PubMed2003

Immunohistochemical analysis of adenocarcinoma of the small intestine: a tissue microarray study.

BACKGROUND: Primary adenocarcinomas of the small intestine are rare, and the genetic mechanisms involved in their carcinogenesis remain unclear. AIM: To examine the expression of candidate proteins in small intestinal adenocarcinomas by immunohistochemistry performed on tissue microarrays (TMAs). METHODS: Twenty seven primary sporadic small intestinal adenocarcinomas were analysed. The TMA technique was validated by comparing immunohistochemical labelling of hMLH1 and hMSH2 on TMAs and the tissue sections they derived from. The expression of Smad4, hMSH6, beta catenin, and p53 was investigated and results compared with those obtained in 14 malignant ampullary tumours. RESULTS: TMA technology with threefold redundancy adequately represented the immunohistochemical pattern of small intestinal adenocarcinomas. Loss of hMLH1 expression, but not hMSH2 or hMSH6, was seen in two of 27 small intestinal adenocarcinomas. All ampullary tumours showed nuclear staining for hMSH2 and hMSH6. One case showed lack of immunostaining for hMLH1. Smad4 expression was absent in five small intestinal adenocarcinomas and two ampullary tumours. Overexpression of p53 was detected in the nuclei of 14 of the 27 small intestinal adenocarcinomas, and five of the 14 ampullary tumours. Nuclear or cytoplasmic expression of beta catenin was present in all specimens. CONCLUSION: Inactivation of the SMAD4/DPC4 gene seems to be involved in small intestinal adenocarcinoma tumorigenesis. Overexpression of p53 and abnormal expression of beta catenin are two common events, unlike the loss of expression of the DNA mismatch repair proteins (hMLH1, hMSH2, and hMSH6). The carcinogenetic process appears to be similar in small intestinal adenocarcinomas and malignant ampullary tumours.

Adenocarcinoma↗
PubMed2002

Primary malignant melanoma of the esophagus: a case report and review of the literature.

The purpose of this report is to describe a new case of primary malignant melanoma of the esophagus (PMME) and to review the recent literature. A 75-year-old man underwent an esophagoscopy for a 3-month history of dysphagia and weight loss. A pigmented polypoïd mass in the lower third of esophagus was discovered, identified by biopsy as a malignant melanoma. No pigmented lesions of the skin or eyes were observed and a diagnosis of PMME was made. A total transhiatal esophagectomy was carried out and 12 months after the operation the patient is disease-free. PMME is a rare neoplasm, with only 238 cases having been reported in the literature. Although characterized by an aggressive biological behavior, esophagectomy can result in a 5-year survival rate of up to 37% of cases, whereas chemotherapy, immunotherapy and radiation therapy currently have no major role in treatment.

Aged↗
PubMed2001

No evidence of somatic FGFR3 mutation in various types of carcinoma.

Germline specific point mutations in the gene encoding fibroblast growth factor receptor 3 (FGFR3) are associated with autosomal dominant human skeletal dysplasia and craniosynostosis syndromes. Mutations identical to the germinal activating mutations found in severe skeletal dysplasias have been identified in certain types of cancer: at low frequency in multiple myeloma and cervix carcinoma and at high frequency in bladder carcinoma. We analysed, by SSCP and sequencing, the prevalence of FGFR3 mutations in 116 primary tumours of various types (upper aerodigestive tract, oesophagus, stomach, lung and skin). The regions analysed encompassed all FGFR3 point mutations previously described in severe skeletal dysplasia and cancers. No mutations were detected in the tumour types examined, suggesting that FGFR3 mutations are restricted to a few tumour types, the evidence to date suggesting that they are very specific to bladder carcinomas.

Bone Diseases, Developmental↗
PubMed2001

Regression of liver fibrosis after biliary drainage in patients with chronic pancreatitis and stenosis of the common bile duct.

BACKGROUND: Chronic obstruction of the common bile duct may cause hepatic fibrosis and secondary biliary cirrhosis. METHODS: We studied liver-biopsy specimens from 11 patients with chronic stenosis of the common bile duct due to chronic pancreatitis; all the patients had undergone liver biopsy before or at the time of surgical biliary decompression and underwent a subsequent liver biopsy for various clinical reasons. The patients were followed as part of a prospective study of 501 patients who had been treated for chronic pancreatitis. Two pathologists, who were unaware of the sequence of specimens, graded fibrosis on a scale of 0 (none) to 3 (cirrhosis). RESULTS: The 11 patients were all men. Chronic pancreatitis was due to alcohol abuse in 10 of the men; 1 had idiopathic disease. The median age at diagnosis was 38 years. The median interval between the first and second liver biopsies was 2.5 years (range, 0.3 to 9.0). The two patients who had restenosis of the biliary anastomosis were excluded from the analysis of fibrosis. In the group of nine patients without restenosis, the second specimen showed significant improvement in fibrosis (P=0.01). The fibrosis improved by two grades in two patients and by one grade in four patients; in three patients, the grade did not change. The pathologists agreed on the grading of specimens from 10 of the 11 patients. CONCLUSIONS: In patients with chronic pancreatitis and stenosis of the common bile duct, liver fibrosis may regress after biliary drainage.

Adult↗