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Dive into the research topics where G. Nkontchou is active.

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Featured researches published by G. Nkontchou.


Hepatology | 2009

Radiofrequency ablation of hepatocellular carcinoma: Long‐term results and prognostic factors in 235 Western patients with cirrhosis

G. Nkontchou; Amel Mahamoudi; Mounir Aout; Nathalie Ganne-Carrié; Véronique Grando; Emmanuelle Coderc; Eric Vicaut; Jean Claude Trinchet; Nicolas Sellier; Michel Beaugrand; Olivier Seror

For the treatment of small hepatocellular carcinoma (HCC), radiofrequency ablation (RFA) is in some centers considered a first‐line therapeutic option. However, such a strategy is still under debate with regard to tumor and patient characteristics. In this single‐center study we assessed the 5‐year survival and prognosis factors in 235 consecutive patients with cirrhosis (Child‐Pugh A/B: 205/30) who received RFA as first‐line treatment for up to three HCC ≤5 cm (307 tumors; mean diameter: 29 ± 10 mm; 53 multinodular forms). Among these patients, 67 satisfied the criteria for resection according to the Barcelona Clinic Liver Cancer. Complete ablation was obtained in 222 patients (94%). Overall, 337 RFA sessions were performed including iterative RFA for recurrence. Major complications occurred in three patients (0.9%), including one treatment‐related death. After 27 ± 20 months of mean follow‐up, local or distant, or both, tumor recurrence occurred in 16, 88, and 11 patients, respectively. Twenty‐nine patients underwent transplantation and were removed from the study at this point. Overall 5‐year, recurrence‐free, and tumor‐free (including results of iterative RFA) survival rates were, respectively, 40%, 17%, and 32%. The overall 5‐year survival rate was 76% for operable patients. Factors associated with overall survival were prothrombin activity (hazard ratio [HR] = 0.97, 0.96–0.98; P < 0.0001) and serum levels of α‐fetoprotein (AFP) (HR = 1.02, 1.02–1.02; P < 0.0001), and factors associated with tumor recurrence were multinodular forms (HR = 2.34; 1.52–3.6; P = 0.0001) and serum AFP levels (HR = 1.015, 1.014–1.016; P = 0.015). Tumor size was associated with local recurrence but not with overall and tumor‐free survival. Conclusion: RFA is a safe and effective first‐line treatment of HCC up to 5 cm in diameter, especially for patients with a single tumor, a low serum AFP level, and well‐preserved liver function. (HEPATOLOGY 2009.)


Hepatology | 2011

Ultrasonographic surveillance of hepatocellular carcinoma in cirrhosis: A randomized trial comparing 3- and 6-month periodicities†‡

Jean-Claude Trinchet; Cendrine Chaffaut; Valérie Bourcier; F. Degos; Jean Henrion; Hélène Fontaine; Dominique Roulot; Ariane Mallat; Sophie Hillaire; Paul Calès; Isabelle Ollivier; Jean-Pierre Vinel; Philippe Mathurin; Jean-Pierre Bronowicki; Valérie Vilgrain; G. Nkontchou; Michel Beaugrand; Sylvie Chevret

Detection of small hepatocellular carcinoma (HCC) eligible for curative treatment is increased by surveillance, but its optimal periodicity is still debated. Thus, this randomized trial compared two ultrasonographic (US) periodicities: 3 months versus 6 months. A multicenter randomized trial was conducted in France and Belgium (43 sites). Patients with histologically proven compensated cirrhosis were randomized into two groups: US every 6 months (Gr6M) or 3 months (Gr3M). For each focal lesion detected, diagnostic procedures were performed according to European Association for the Study of the Liver guidelines. Cumulative incidence of events was estimated, then compared using Grays test. The prevalence of HCC ≤30 mm in diameter was the main endpoint. A sample size of 1,200 patients was required. A total of 1,278 patients were randomized (Gr3M, n = 640; Gr6M, n = 638; alcohol 39.2%, hepatitis C virus 44.1%, hepatitis B virus 12.5%). At least one focal lesion was detected in 358 patients (28%) but HCC was confirmed in only 123 (9.6%) (uninodular 58.5%, ≤30 mm in diameter 74%). Focal‐lesion incidence was not different between Gr3M and Gr6M groups (2‐year estimates, 20.4% versus 13.2%, P = 0.067) but incidence of lesions ≤10 mm was increased (41% in Gr3M versus 28% in Gr6M, P = 0.002). No difference in either HCC incidence (P = 0.13) or in prevalence of tumors ≤30 mm in diameter (79% versus 70%, P = 0.30) was observed between the randomized groups. Conclusion: US surveillance, performed every 3 months, detects more small focal lesions than US every 6 months, but does not improve detection of small HCC, probably because of limitations in recall procedures. (HEPATOLOGY 2011;)


BMC Cancer | 2010

A phase II open label trial evaluating safety and efficacy of a telomerase peptide vaccination in patients with advanced hepatocellular carcinoma

Tim F. Greten; Alejandro Forner; Firouzeh Korangy; G. Nkontchou; Nathalie Barget; Carmen Ayuso; Lars A. Ormandy; Michael P. Manns; Michel Beaugrand; Jordi Bruix

BackgroundThe sole effective option for patients with advanced HCC is sorafenib and there is an urgent need to develop new therapeutic approaches. Immunotherapy is a promising option that deserves major investigation. In this open label, single arm clinical trial, we analyzed the effect of a low dose cyclophosphamide treatment in combination with a telomerase peptide (GV1001) vaccination in patients with advanced HCC.Methods40 patients with advanced HCC were treated with 300 mg/m2 cyclophosphamide on day -3 followed by GM-CSF + GV1001 vaccinations on days 1, 3, 5, 8, 15, 22, 36 followed by 4-weekly injections. Primary endpoint of this phase II trial was tumor response; secondary endpoints evaluated were TTP, TTSP, PFS, OS, safety and immune responses.ResultsNone of the patients had a complete or partial response to treatment, 17 patients (45.9%) demonstrated a stable disease six months after initiation of treatment. The median TTP was 57.0 days; the median TTSP was estimated to be 358.0 days. Cyclophosphamide, GV1001 and GM-CSF treatment were well tolerated and most adverse events, which were of grade 1 or 2, were generally related to the injection procedure and injection site reactions. GV1001 treatment resulted in a decrease in CD4+CD25+Foxp3+ regulatory T cells; however, no GV1001 specific immune responses were detected after vaccination.ConclusionsLow dose cyclophosphamide treatment followed by GV1001 vaccinations did not show antitumor efficacy as per tumor response and time to progression. Further studies are needed to analyze the effect of a combined chemo-immunotherapy to treat patients with HCC.Trial registrationNCT00444782


Radiology | 2008

Large (≥5.0-cm) HCCs: Multipolar RF Ablation with Three Internally Cooled Bipolar Electrodes—Initial Experience in 26 Patients

Olivier Seror; G. Nkontchou; Medhat Ibraheem; Yves Ajavon; Corinne Barrucand; Nathalie Ganne; Emmanuelle Coderc; Jean Claude Trinchet; Michel Beaugrand; Nicolas Sellier

PURPOSE To prospectively evaluate the safety and effectiveness of percutaneous multipolar radiofrequency (RF) ablation for the treatment of large (>or=5.0 cm in diameter) hepatocellular carcinomas (HCCs). MATERIALS AND METHODS Twenty-six patients (four women, 22 men; median age, 72 years) with cirrhosis (Child-Pugh class A disease, 22 patients; Child-Pugh class B disease, four patients) and at least one 5.0-9.0-cm-diameter HCC without invasion of the portal trunk or main portal branches were treated with multipolar RF ablation performed by a single operator. The procedure was performed with three separate bipolar linear internally cooled electrodes with ultrasonographic guidance. Twenty-seven of the 33 tumors treated had a diameter of 5.0 cm or greater (median diameter, 5.7 cm; range, 5.0-8.5 cm); 12 of these 27 tumors were infiltrative, and four invaded segmental portal vein branches. Ten patients had a serum alpha-fetoprotein level higher than 400 microg/L. Results were assessed by using computed tomography. Primary effectiveness, complications, tumor progression, and survival rates were recorded. Probabilities of survival were calculated by using the Kaplan-Meier method. RESULTS One to two RF ablation procedures per patient (mean, 1.15 +/- 0.43 [standard deviation]) led to the complete ablation of 22 (81%) of the 27 tumors (18 tumors after one and four tumors after two procedures), including three tumors that showed segmental portal vein invasion. All patients experienced postablation syndrome, and one experienced subcapsular hematoma and a segmental liver infarct, but no major complication occurred. After a mean follow-up of 14 months (range, 3-34 months), local and distant tumor progression and actual survival rates were 14% (three of 22), 24% (five of 21), and 65% (17 of 26), respectively. The probabilities of 1- and 2-year survival, respectively, were 68% (95% confidence interval: 49%, 86%) and 56% (95% confidence interval: 51%, 81%). CONCLUSION HCCs larger than 5.0 cm (but smaller than 9.0 cm)--even those that are infiltrative and those that involve a segmental portal vein--can be completely and safely ablated with multipolar RF ablation.


Hepatology | 2011

Telomerase gene mutations are associated with cirrhosis formation

Daniel Hartmann; Ujala Srivastava; Michaela Thaler; Karin N. Kleinhans; G. Nkontchou; Annika Scheffold; Kerstin Bauer; Ramona F. Kratzer; Natalia Kloos; Sarah-Fee Katz; Zhangfa Song; Yvonne Begus-Nahrmann; Alexander Kleger; Guido von Figura; Pavel Strnad; André Lechel; Cagatay Günes; Andrej Potthoff; Katja Deterding; Heiner Wedemeyer; Zhenyu Ju; Ge Song; Feng Xiao; Sonja Gillen; Hubert Schrezenmeier; Thomas Mertens; Marianne Ziol; Helmut Friess; Michael Jarek; Michael P. Manns

Telomere shortening impairs liver regeneration in mice and is associated with cirrhosis formation in humans with chronic liver disease. In humans, telomerase mutations have been associated with familial diseases leading to bone marrow failure or lung fibrosis. It is currently unknown whether telomerase mutations associate with cirrhosis induced by chronic liver disease. The telomerase RNA component (TERC) and the telomerase reverse transcriptase (TERT) were sequenced in 1,121 individuals (521 patients with cirrhosis induced by chronic liver disease and 600 noncirrhosis controls). Telomere length was analyzed in patients carrying telomerase gene mutations. Functional defects of telomerase gene mutations were investigated in primary human fibroblasts and patient‐derived lymphocytes. An increased incidence of telomerase mutations was detected in cirrhosis patients (allele frequency 0.017) compared to noncirrhosis controls (0.003, P value 0.0007; relative risk [RR] 1.859; 95% confidence interval [CI] 1.552‐2.227). Cirrhosis patients with TERT mutations showed shortened telomeres in white blood cells compared to control patients. Cirrhosis‐associated telomerase mutations led to reduced telomerase activity and defects in maintaining telomere length and the replicative potential of primary cells in culture. Conclusion: This study provides the first experimental evidence that telomerase gene mutations are present in patients developing cirrhosis as a consequence of chronic liver disease. These data support the concept that telomere shortening can represent a causal factor impairing liver regeneration and accelerating cirrhosis formation in response to chronic liver disease. (HEPATOLOGY 2011;)


Journal of Hepatology | 2010

Insulin resistance, serum leptin, and adiponectin levels and outcomes of viral hepatitis C cirrhosis.

G. Nkontchou; Jean-Philippe Bastard; Marianne Ziol; Mounir Aout; Emmanuel Cosson; Nathalie Ganne-Carrié; Véronique Grando-Lemaire; Dominique Roulot; Jacqueline Capeau; Jean-Claude Trinchet; Eric Vicaut; Michel Beaugrand

BACKGROUND & AIMS Mechanisms linking obesity and unfavourable outcomes in patients with viral hepatitis C (HCV) cirrhosis are not well understood. Obesity is associated with insulin resistance, increased leptin, and decreased adiponectin serum levels. METHODS We assessed the predictive value of those factors for the occurrence of hepatocellular carcinoma (HCC) and liver-related death or transplantation in a cohort of 248 patients (mean age 58 (12 years, BMI 25.4 ± 4.4 kg/m(2)) with compensated HCV cirrhosis and persistent infection prospectively followed and screened for HCC. RESULTS The mean baseline serum levels of adiponectin and leptin were 16.8 ± 15 mg/L and 16.8 ± 19 ng/ml, respectively. The mean homeostasis model assessment of insulin resistance (HOMA) index was 3.8 ± 3; median 2.9. After a median follow-up of 72 months, 61 patients developed HCC, 58 died of liver causes, and 17 were transplanted. The incidences (Kaplan Meier) of HCC were 7%, 18%, and 27% at 5 years (p=0.017) and of liver-related death or transplantation 15%, 15% and 29% (p=0.002) according to the lowest, middle and highest tertile of HOMA, respectively. In multivariate analysis, the HOMA index was associated with HCC occurrence (HR=1.10, [1.01-1.21] p=0.026) and was a strong predictor of liver-related death or transplantation (HR=1.13, [1.07-1.21] p<0.0001). Serum levels of adiponectin and leptin were not associated with the outcome. CONCLUSIONS In patients with compensated HCV cirrhosis, insulin resistance but not serum levels of adiponectin and leptin predicted the occurrence of HCC and of liver-related death or transplantation.


Hepatology | 2009

Myeloperoxidase and superoxide dismutase 2 polymorphisms comodulate the risk of hepatocellular carcinoma and death in alcoholic cirrhosis

P. Nahon; Angela Sutton; Pierre Rufat; Marianne Ziol; Hassan Akouche; Christelle Laguillier; Nathalie Charnaux; Nathalie Ganne-Carrié; Véronique Grando-Lemaire; G. Nkontchou; Jean-Claude Trinchet; Liliane Gattegno; Dominique Pessayre; Michel Beaugrand

Alcohol increases reactive oxygen species (ROS) formation in hepatocyte mitochondria and by reduced nicotinamide adenine dinucleotide phosphate oxidases and myeloperoxidase (MPO) in Kupffer cells and liver‐infiltrating neutrophils. Manganese superoxide dismutase (MnSOD) converts superoxide anion into hydrogen peroxide, which, unless detoxified by glutathione peroxidase or catalase (CAT), can form the hydroxyl radical with iron. Our aim was to determine whether Ala16Val‐superoxide dismutase 2 (SOD2), G‐463A‐MPO, or T‐262C‐CAT dimorphisms modulate the risks of hepatocellular carcinoma (HCC) and death in alcoholic cirrhosis. Genotypes and the hepatic iron score were assessed in 190 prospectively followed patients with alcoholic cirrhosis. During follow‐up (61.1 ± 2.7 months), 51 patients developed HCC, and 71 died. The T‐262C‐CAT dimorphism did not modify hepatic iron, HCC, or death. The GG‐MPO genotype did not modify iron but increased the risks of HCC and death. The hazard ratio (HR) was 4.7 (2.1–10.1) for HCC and 3.6 (1.9–6.7) for death. Carriage of one or two Ala‐SOD2 allele(s) was associated with higher liver iron scores and higher risks of HCC and death. The 5‐year incidence of HCC was 34.4% in patients with both the GG‐MPO genotype and one or two Ala‐SOD2 alleles, 5.1% in patients with only one of these two traits, and 0% in patients with none of these traits. Corresponding 5‐year death rates were 37.6%, 11.6%, and 5%. Conclusion: The combination of the GG‐MPO genotype (leading to high MPO expression) and at least one Ala‐SOD2 allele (associated with high liver iron score) markedly increased the risks of HCC occurrence and death in patients with alcoholic cirrhosis. (HEPATOLOGY 2009.)


Cancer Prevention Research | 2012

Effect of Long-term Propranolol Treatment on Hepatocellular Carcinoma Incidence in Patients with HCV-Associated Cirrhosis

G. Nkontchou; Mounir Aout; Amel Mahmoudi; Dominique Roulot; Valérie Bourcier; Véronique Grando-Lemaire; Nathalie Ganne-Carrié; Jean-Claude Trinchet; Eric Vicaut; Michel Beaugrand

Propranolol bears antioxidant, anti-inflammatory, and antiangiogenic properties and antitumoral effects and therefore is potentially active in the prevention of hepatocellular carcinoma (HCC). We retrospectively assessed the impact of propranolol treatment on HCC occurrence in a cohort of 291 patients with compensated viral C (HCV) cirrhosis, prospectively followed and screened for HCC detection. Of the 291 patients included in the cohort, 93 patients [50 males: mean age, 59.5 ± 12 years; body mass index (BMI), 25.7 ± 4.4 kg/m2; and platelet count, 111 ± 53 Giga/L] developed esophageal varices (OV) or had OV at inclusion and 198 patients (111 males: mean age, 55.8 ± 13 years; BMI, 25.7 ± 5 kg/m2; platelet count, 137 ± 59 Giga/L) did not. Among patients with OV, 50 received treatment by propranolol. During a median follow-up of 54 months interquartile range (32–82), 61 patients developed an HCC. The 3- and 5-year HCC incidence was 4% and 4%, and 10% and 20% for patients treated and not treated by propranolol, respectively (Gray test, P = 0.03). In multivariate analysis, propranolol treatment was associated with a decrease risk of HCC occurrence [HR, 0.25; 95% confidence interval (CI), 0.09–0.65; P = 0.004], and was the only independent predictive factor of HCC occurrence in patients with OV (HR, 0.16; CI, 0.06–0.45; P = 0.0005). The benefit of propranolol was further supported by propensity scores analyses. Conclusion: This retrospective long-term observational study suggests that propranolol treatment may decrease HCC occurrence in patients with HCV cirrhosis. These findings need to be verified by prospective clinical trial. Cancer Prev Res; 5(8); 1007–14. ©2012 AACR.


Journal of Vascular and Interventional Radiology | 2005

Radiofrequency Ablation for the Treatment of Liver Tumors in the Caudate Lobe

Olivier Seror; D. Haddar; G. Nkontchou; Yves Ajavon; Jean-Claude Trinchet; Michel Beaugrand; Nicolas Sellier

PURPOSE To evaluate the effectiveness of radiofrequency (RF) ablation for liver tumors located in the caudate lobe. MATERIALS AND METHODS Ten patients (46-79 years of age; median, 70 y), eight with hepatocellular carcinoma (HCC) and cirrhosis and two with colorectal metastases in the caudate lobe, were treated with 5.8% NaCl tissue-perfused monopolar (n=7) or bipolar (n=3) RF ablation. The median tumor diameter was 41 mm (range, 25-70 mm). Procedures were performed under ultrasound and computed tomography (CT) guidance in eight and two patients, respectively. One month later, the treatment response was assessed by CT. RESULTS Transhepatic right intercostal and transomental anterior epigastric routes were used for tumor puncture in eight and two patients, respectively. The entire RF ablation treatment required one or two procedures (median, 1.5), including two to 15 electrode repositionings (median, 6). After RF ablation procedure, one patient experienced jaundice that resolved spontaneously. In one patient, CT follow-up showed asymptomatic segmental biliary duct dilations. Median total hospital stay was 3 days (range, 2-9 d). Complete ablation was achieved in nine of 10 tumors. In one patient, ethanol ablation was necessary to complete RF ablation treatment. After a median follow up of 9.5 months (range, 5-25 mo), three patients remained tumor-free and seven had tumor relapse: two local, four distant, and one mixed. Repeat RF ablation was successfully performed in four cases. CONCLUSION RF ablation of liver tumors located in the caudate lobe is effective despite the deep location of tumors and the vicinity of major vessels.


Radiology | 2016

Hepatocellular Carcinoma within Milan Criteria: No-Touch Multibipolar Radiofrequency Ablation for Treatment—Long-term Results

Olivier Seror; G. Nkontchou; Jean-Charles Nault; Rabahi Y; Pierre Nahon; Ganne-Carrié N; Grando; Zentar N; Michel Beaugrand; Jean-Claude Trinchet; Diallo A; Nicolas Sellier

Purpose To assess the long-term outcome in 108 consecutive patients treated with no-touch multibipolar radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) that met the Milan criteria. Materials and Methods This retrospective study was approved by the ethical review board, and the need to obtain informed consent was waived. Between November 1, 2006, and December 31, 2011, 132 HCC tumors (diameter, 10-45 mm; 39 tumors ≥ 30 mm) in 108 consecutive patients (106 with cirrhosis) that met Milan criteria were treated with no-touch multibipolar RFA, which consisted of activating, in bipolar mode, three or four electrodes inserted just beyond the tumor margins. Follow-up was performed every 3 months for 2 years and every 6 months thereafter with computed tomographic or magnetic resonance imaging. Survival probabilities were computed by using the Kaplan-Meier method. Predictive factors of tumor progression and overall survival were assessed by using the Cox proportional hazard model. Results No technical failure occurred, and complete ablation was achieved for all the nodules. After a median of 40.5 months (range, 2-84 months) of follow-up, 3- and 5-year local and overall tumor progression-free survival were 96%, 94%, 52%, and 32%, respectively. Neither tumor diameter greater than 30 mm nor location abutting a large vessel were associated with local tumor progression. Tumor diameter greater than 30 mm was the only parameter predictive of overall tumor progression (P = .0036). Independent factors associated with shorter overall survival were Child-Pugh class B disease, age greater than 65 years, and platelet count of less than 150 g/L (P < .003). Three major complications occurred (2.7%): hemothorax in one patient and liver failure in two, with major portal-systemic shunts. One patient (0.9%) died, and one underwent transplantation. Conclusion No-touch multibipolar RFA for HCC tumors that meet Milan criteria provides a high local tumor progression-free survival rate. An ongoing randomized trial might help to clarify the role of this new approach for the treatment of early HCC. (©) RSNA, 2016 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on March 30, 2016.

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