Denis Pezet
French Institute of Health and Medical Research
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Featured researches published by Denis Pezet.
Journal of Clinical Oncology | 2007
Laurent Bedenne; Pierre Michel; Olivier Bouché; Chantal Milan; Christophe Mariette; Thierry Conroy; Denis Pezet; Bernard Roullet; Jean-François Seitz; Jean-Philippe Herr; Bernard Paillot; Patrick Arveux; Franck Bonnetain; Christine Binquet
PURPOSE Uncontrolled studies suggest that chemoradiation has similar efficacy as surgery for esophageal cancer. Therefore, a randomized trial was carried out to compare, in responders only, chemoradiation alone with chemoradiation followed by surgery in patients with locally advanced tumors. PATIENTS AND METHODS Eligible patients had operable T3N0-1M0 thoracic esophageal cancer. Patients received two cycles of fluorouracil (FU) and cisplatin (days 1 to 5 and 22 to 26) and either conventional (46 Gy in 4.5 weeks) or split-course (15 Gy, days 1 to 5 and 22 to 26) concomitant radiotherapy. Patients with response and no contraindication to either treatment were randomly assigned to surgery (arm A) or continuation of chemoradiation (arm B; three cycles of FU/cisplatin and either conventional [20 Gy] or split-course [15 Gy] radiotherapy). Chemoradiation was considered equivalent to surgery if the difference in 2-year survival rate was less than 10%. RESULTS Of 444 eligible patients, 259 were randomly assigned; 230 patients (88.8%) had epidermoid cancer, and 29 (11.2%) had glandular carcinoma. Two-year survival rate was 34% in arm A versus 40% in arm B (hazard ratio for arm B v arm A = 0.90; adjusted P = .44). Median survival time was 17.7 months in arm A compared with 19.3 months in arm B. Two-year local control rate was 66.4% in arm A compared with 57.0% in arm B, and stents were less required in the surgery arm (5% in arm A v 32% in arm B; P < .001). The 3-month mortality rate was 9.3% in arm A compared with 0.8% in arm B (P = .002). Cumulative hospital stay was 68 days in arm A compared with 52 days in arm B (P = .02). CONCLUSION Our data suggest that, in patients with locally advanced thoracic esophageal cancers, especially epidermoid, who respond to chemoradiation, there is no benefit for the addition of surgery after chemoradiation compared with the continuation of additional chemoradiation.
Nature Medicine | 2014
Alain R. Thierry; Florent Mouliere; Safia El Messaoudi; Caroline Mollevi; Evelyne Lopez-Crapez; Fanny Rolet; Brigitte Gillet; Céline Gongora; Pierre Déchelotte; Bruno Robert; Maguy Del Rio; Pierre-Jean Lamy; Frédéric Bibeau; Michelle Nouaille; Virginie Loriot; Anne-Sophie Jarrousse; Franck Molina; Muriel Mathonnet; Denis Pezet; Marc Ychou
Assessment of KRAS status is mandatory in patients with metastatic colorectal cancer (mCRC) before applying targeted therapy. We describe here a blinded prospective study to compare KRAS and BRAF mutation status data obtained from the analysis of tumor tissue by routine gold-standard methods and of plasma DNA using a quantitative PCR–based method specifically designed to analyze circulating cell-free DNA (cfDNA). The mutation status was determined by both methods from 106 patient samples. cfDNA analysis showed 100% specificity and sensitivity for the BRAF V600E mutation. For the seven tested KRAS point mutations, the method exhibited 98% specificity and 92% sensitivity with a concordance value of 96%. Mutation load, expressed as the proportion of mutant alleles in cfDNA, was highly variable (0.5–64.1%, median 10.5%) among mutated samples. CfDNA was detected in 100% of patients with mCRC. This study shows that liquid biopsy through cfDNA analysis could advantageously replace tumor-section analysis and expand the scope of personalized medicine for patients with cancer.
Journal of Clinical Oncology | 2008
Erick Gamelin; Remy Delva; Jacques Jacob; Yacine Merrouche; Jean Luc Raoul; Denis Pezet; Etienne Dorval; Gilles Piot; Alain Morel; Michèle Boisdron-Celle
PURPOSE A phase III, multicenter, randomized study compared conventional dosing of fluorouracil (FU) plus folinic acid with pharmacokinetically guided FU dose adjustment in terms of response, tolerability, and survival. PATIENTS AND METHODS Two hundred eight patients with measurable metastatic colorectal cancer were randomly assigned to one of two arms: arm A (104 patients; 96 assessable), in which the FU dose was calculated based on body-surface area; and arm B (104 patients; 90 assessable), in which the FU dose was individually determined using pharmacokinetically guided adjustments. The initial regimen was 1,500 mg/m(2) FU plus 200 mg/m(2) folinic acid infusion during a continuous 8-hour period administered once weekly. FU doses were adjusted weekly in arm B based on a single-point measurement of FU plasma concentrations at steady state until the therapeutic range (targeted area under the curve 20-25 mg x h x L(-1)) previously established in other studies was reached. RESULTS An intent-to-treat analysis of the 208 patients showed the objective response rate was 18.3% in arm A and 33.7% in arm B (P = .004). Median overall survival was 16 months in arm A and 22 months in arm B (P = .08). The mean FU dose throughout treatment was 1,500 mg/m(2)/wk in arm A and 1,790 +/- 386 mg/m(2)/wk (range, 900 to 3,300 mg/m(2)/wk) in arm B. Toxic adverse effects were significantly more frequent and severe in arm A compared with arm B (P = .003). CONCLUSION Individual FU dose adjustment based on pharmacokinetic monitoring resulted in significantly improved objective response rate, a trend to higher survival rate, and fewer grade 3/4 toxicities. These results support the value of pharmacokinetically guided management of FU dose in the treatment of metastatic colorectal patients.
Journal of Clinical Oncology | 2014
Christophe Mariette; Laetitia Dahan; F. Mornex; Emilie Maillard; Bernard Meunier; Valérie Boige; Denis Pezet; William B. Robb; Valérie Le Brun-Ly; Jean-François Bosset; Jean-Yves Mabrut; Jean-Pierre Triboulet; Laurent Bedenne; Jean-François Seitz
PURPOSE Although often investigated in locally advanced esophageal cancer (EC), the impact of neoadjuvant chemoradiotherapy (NCRT) in early stages is unknown. The aim of this multicenter randomized phase III trial was to assess whether NCRT improves outcomes for patients with stage I or II EC. METHODS The primary end point was overall survival. Secondary end points were disease-free survival, postoperative morbidity, in-hospital mortality, R0 resection rate, and prognostic factor identification. From June 2000 to June 2009, 195 patients in 30 centers were randomly assigned to surgery alone (group S; n = 97) or NCRT followed by surgery (group CRT; n = 98). CRT protocol was 45 Gy in 25 fractions over 5 weeks with two courses of concomitant chemotherapy composed of fluorouracil 800 mg/m(2) and cisplatin 75 mg/m(2). We report the long-term results of the final analysis, after a median follow-up of 93.6 months. RESULTS Pretreatment disease was stage I in 19.0%, IIA in 53.3%, and IIB in 27.7% of patients. For group CRT compared with group S, R0 resection rate was 93.8% versus 92.1% (P = .749), with 3-year overall survival rate of 47.5% versus 53.0% (hazard ratio [HR], 0.99; 95% CI, 0.69 to 1.40; P = .94) and postoperative mortality rate of 11.1% versus 3.4% (P = .049), respectively. Because interim analysis of the primary end point revealed an improbability of demonstrating the superiority of either treatment arm (HR, 1.09; 95% CI, 0.75 to 1.59; P = .66), the trial was stopped for anticipated futility. CONCLUSION Compared with surgery alone, NCRT with cisplatin plus fluorouracil does not improve R0 resection rate or survival but enhances postoperative mortality in patients with stage I or II EC.
CardioVascular and Interventional Radiology | 2003
R. Guillon; J.M. Garcier; Armand Abergel; R. Mofid; V. Garcia; T. Chahid; A. Ravel; Denis Pezet; L. Boyer
AbstractPurpose: To assess the endovascular treatment of splenic artery aneurysms and false aneurysms. Methods: Twelve patients (mean age 59 years, range 47–75 years) with splenic artery aneurysm (n = 10) or false aneurysm (n = 2) were treated. The lesion was asymptomatic in 11 patients; hemobilia was observed in one patient. The lesion was juxta-ostial in one case, located on the intermediate segment of the splenic artery in four, near the splenic hilus in six, and affected the whole length of the artery in one patient. In 10 cases, the maximum lesion diameter was greater than 2 cm; in one case 30% growth of an aneurysm 18 mm in diameter had occurred in 6 months; in the last case, two distal aneurysms were associated (17 and 18 mm in diameter). In one case, stent-grafting was attempted; one detachable balloon occlusion was performed; the 10 other patients were treated with coils. Results: Endovascular treatment was possible in 11 patients (92%) (one failure: stenting attempt). In four cases among 11, the initial treatment was not successful (residual perfusion of aneurysm); surgical treatment was carried out in one case, and a second embolization in two. Thus in nine cases (75%) endovascular treatment was successful: complete and persistent exclusion of the aneurysm but with spleen perfusion persisting at the end of follow-up on CT scans (mean 13 months). An early and transient elevation of pancreatic enzymes was observed in four cases. Conclusion: Ultrasound and CT have made the diagnosis of splenic artery aneurysm or false aneurysm more frequent. Endovascular treatment, the morbidity of which is low, is effective and spares the spleen.
Clinical Cancer Research | 2008
Marie-Christine Etienne-Grimaldi; Jean-Louis Formento; Mireille Francoual; Eric Francois; Patricia Formento; Nicole Renée; Pierre Laurent-Puig; Maurice Chazal; Daniel Benchimol; Jean-Robert Delpero; Christian Letoublon; Denis Pezet; Jean-François Seitz; Gérard Milano
Purpose: K-Ras mutations predict resistance to anti–epidermal growth factor receptor (EGFR) monoclonal antibodies. Because combinations of anti-EGFR with 5-fluorouracil (5-FU)-based chemotherapy are promising treatments, we analyzed the effect of K-Ras mutations in patients having received exclusive 5-FU therapy. Experimental Design: This study was conducted on 93 stage IV colorectal cancer patients with unresectable measurable liver metastasis receiving 5-FU-leucovorin (56 men and 37 women; 77 cancer deaths). Liver metastases (n = 93) along with primary tumors (n = 48) were analyzed for K-Ras mutations (codons 12 and 13), p53 mutations (exons 4-9), p53 polymorphism (codon 72), thymidylate synthase (TS) polymorphism (28-bp repeats including G>C mutation), methylenetetrahydrofolate reductase polymorphism (677C>T, 1298A>C), thymidylate synthase (TS) activity, dihydropyrimidine dehydrogenase activity, folylpolyglutamate synthase activity, and p53 protein expression. Results: Thirty-six of 93 (38.7%) metastases were K-Ras mutated (30 at codon 12 and 6 at codon 13). Mutated primary tumors (16 of 48) matched perfectly with mutated metastases. The additional analyzed tumor markers were not different between K-Ras mutated and wild-type tumors. The objective response rate was 37%: 44.4% in K-Ras mutated versus 32.1% in wild-type K-Ras metastasis (P = 0.27). Low TS activity in metastasis was the only significant predictor of tumor response (P = 0.047). K-Ras status did not influence specific survival. Conclusions: The present data indicate a perfect concordance of K-Ras mutations between primary and liver metastasis and suggest that any predictive and/or prognostic value of K-Ras mutations in treatments combining anti-EGFR monoclonal antibodies with 5-FU should be exclusively linked to the anti-EGFR agent.
PLOS ONE | 2013
Emmanuel Buc; Damien Dubois; Pierre Sauvanet; Jennifer Raisch; Julien Delmas; Arlette Darfeuille-Michaud; Denis Pezet; Richard Bonnet
Some Escherichia coli strains produce toxins designated cyclomodulins (CMs) which interfere with the eukaryotic cell cycle of host cells, suggesting a possible link between these bacteria and cancers. There are relatively few data available concerning the colonization of colon tumors by cyclomodulin- and genotoxic-producing E. coli. We did a qualitative and phylogenetic analysis of mucosa-associated E. coli harboring cyclomodulin-encoding genes from 38 patients with colorectal cancer (CRC) and 31 with diverticulosis. The functionality of these genes was investigated on cell cultures and the genotoxic activity of strains devoid of known CM-encoding gene was investigated. Results showed a higher prevalence of B2 phylogroup E. coli harboring the colibatin-producing genes in biopsies of patients with CRC (55.3%) than in those of patients with diverticulosis (19.3%), (p<0.01). Likewise, a higher prevalence of B2 E. coli harboring the CNF1-encoding genes in biopsies of patients with CRC (39.5%) than in those of patients with diverticulosis (12.9%), (p = 0.01). Functional analysis revealed that the majority of these genes were functional. Analysis of the ability of E. coli to adhere to intestinal epithelial cells Int-407 indicated that highly adherent E. coli strains mostly belonged to A and D phylogroups, whatever the origin of the strains (CRC or diverticulosis), and that most E. coli strains belonging to B2 phylogroup displayed very low levels of adhesion. In addition, 27.6% (n = 21/76) E. coli strains devoid of known cyclomodulin-encoding genes induced DNA damage in vitro, as assessed by the comet assay. In contrast to cyclomodulin-producing E. coli, these strains mainly belonged to A or D E. coli phylogroups, and exhibited a non significant difference in the distribution of CRC and diverticulosis specimens (22% versus 32.5%, p = 0.91). In conclusion, cyclomodulin-producing E. coli belonging mostly to B2 phylogroup colonize the colonic mucosa of patients with CRC.
Gut | 2014
Antony Cougnoux; Guillaume Dalmasso; Ruben Martinez; Emmanuel Buc; Julien Delmas; Lucie Gibold; Pierre Sauvanet; Claude Darcha; Pierre Déchelotte; Mathilde Bonnet; Denis Pezet; Harald Wodrich; Arlette Darfeuille-Michaud; Richard Bonnet
Background Escherichia coli strains harbouring the pks island (pks+ E. coli) are often seen in human colorectal tumours and have a carcinogenic effect independent of inflammation in an AOM/IL-10−/− (azoxymethane/interleukin) mouse model. Objective To investigate the mechanism sustaining pks+ E. coli-induced carcinogenesis. Method Underlying cell processes were investigated in vitro and in vivo (xenograft model) using intestinal epithelial cells infected by pks+ E. coli or by an isogenic mutant defective for pks (pks− E. coli). The results were supported by data obtained from an AOM/DSS (azoxymethane/dextran sodium sulphate) colon cancer mouse model and from human colon cancer biopsy specimens colonised by pks+ E. coli or pks− E. coli. Results Colibactin-producing E. coli enhanced tumour growth in both xenograft and AOM/DSS models. Growth was sustained by cellular senescence (a direct consequence of small ubiquitin-like modifier (SUMO)-conjugated p53 accumulation), which was accompanied by the production of hepatocyte growth factor (HGF). The underlying mechanisms involve microRNA-20a-5p, which targets SENP1, a key protein regulating p53 deSUMOylation. These results are consistent with the expression of SENP1, microRNA-20a-5p, HGF and phosphorylation of HGF receptor found in human and mouse colon cancers colonised by pks+ E. coli. Conclusion These data reveal a new paradigm for carcinogenesis, in which colibactin-induced senescence has an important role.
Clinical Cancer Research | 2014
Mathilde Bonnet; Emmanuel Buc; Pierre Sauvanet; Claude Darcha; Damien Dubois; Bruno Pereira; Pierre Déchelotte; Richard Bonnet; Denis Pezet; Arlette Darfeuille-Michaud
Purpose: The intestinal microbiota is potentially involved in the development of colorectal carcinoma via various mechanisms. Escherichia coli are commensal bacteria of the human gut microbiota, but some pathogenic strains have acquired the ability to induce chronic inflammation and/or produce toxins, such as cyclomodulin, which could participate in the carcinogenesis process. Here, we analyzed the E. coli population associated with mucosa of patients with colon cancer in relation to clinicopathologic characteristics. We assessed carcinogenic properties of a colon cancer–associated E. coli strain in multiple intestinal neoplasia (Min) mice. Experimental design: Mucosa-associated or internalized E. coli were quantified and characterized from tumors and mucosa of patients with colon cancer and the healthy mucosa of diverticulosis controls. Min mice were inoculated with a colon cancer–associated E. coli strain (11G5). The number of colonic polyps was evaluated at 7 weeks after infection. Results: An increased level of mucosa-associated and internalized E. coli was observed in the tumors compared with normal tissue. A relationship between poor prognostic factors for colon cancer (tumor–node–metastasis stage) and colonization of mucosa by E. coli was observed. Pathogenic cyclomodulin-positive E. coli strains were more prevalent on mucosa of patients with stages III/IV than those with stage I colon cancer. Proliferative index and E. coli colonization level of the mucosa distant from the tumor significantly correlated. Min mice infected with the E. coli strain 11G5 displayed a marked increase in the number of visible colonic polyps compared with controls. Conclusion: These findings support that pathogenic E. coli could be a cofactor in pathogenesis of colorectal cancer. Clin Cancer Res; 20(4); 859–67. ©2013 AACR.
American Journal of Surgery | 2000
Karem Slim; Jacques Bousquet; Fabrice Kwiatkowski; Guy Lescure; Denis Pezet; Jacques Chipponi
BACKGROUND Laparoscopic fundoplication is a well-established surgical option for the treatment of gastroesophageal reflux disease. The aim of this study was to assess the surgical outcomes from the patients point of view by using a validated quality of life instrument. METHODS Fifty patients have been prospectively included. All patients underwent a standardized 270-degree posterior fundoplication. Quality of life was measured by the Gastrointestinal Quality of Life Index (GIQLI), a 36-item-questionnaire. The patients received the questionnaire before surgery, and 3 months and 1 year after surgery. RESULTS Preoperative score was 95.6+/-21 points. The score increased significantly (P <0.0005) at 3 months (103.6+/-16) and 1 year (111.4+/-22) after surgery. This improvement concerned the four domains of the questionnaire (symptoms, social functioning, physical status, and emotions). The score in patients at 1 year remained, however, significantly lower than that in healthy persons (126+/-18). CONCLUSIONS GIQLI is a sensitive tool to assess surgical outcomes after fundoplication. The quality of life after surgery did not reach the level of healthy population, not because of failure of surgery to treat GERD but probably because of functional dyspepsia that was present prior to surgery and did not change after fundoplication.