Biomedical subjects

J Faivre

Publications and source records attributed to J Faivre.

At least 37 records · Page 2Linked to original sources

PubMed2004

Dietary patterns and the adenomacarcinoma sequence of colorectal cancer.

BACKGROUND: Food components of a diet are highly related, so that building up dietary patterns may help understand the relationship between chronic diseases and diet, and identify high risk groups that need preventive advice. AIM: The aim of this study was to determine dietary patterns associated with the colorectal adenoma-carcinoma pathway. METHODS: We performed a two-step analysis using first principal component analysis to select the most appropriate food groups, then a hierarchical agglomerative clustering method, in order to determine dietary patterns in 1372 subjects included in a case-control study. Patients with hyperplastic polyps (n = 103), adenomas < 10 mm, (n = 154) or larger adenomas (n = 208) were then compared with polyp-free controls (n = 426), and colorectal cancer cases (n = 171) compared with population controls (n = 309) using unconditional logistic regression adjusted on age and gender. RESULTS: Cluster analysis determined five food patterns. Cluster 1 identified a low-energy diet; cluster 2 a high-starch, highfat, and low-fruit diet; cluster 3 a high-processed meat, -energy, -alcohol, and -starchy foods diet; cluster 4 a high-fish, -cereals, -honey, -olive oil, -fruit and -vegetables diet; and cluster 5 a high-flour, -sugar, -chocolate, -animal fats, and -eggs diet. Logistic regression identified cluster 2 [corrected] as significantly associated with risk of small adenomas (OR = 1.7; 95% confidence interval 1.0-2.7), large adenomas (OR = 1.9; 1.2-3.0) and cancers (OR = 1.7; 1.1-2.8) compared with cluster 1 [corrected] Cluster 4 diet was inversely associated with risk of small adenomas (OR = 0.4; 0.2-1.0). There was no relationship between patterns and risk of hyperplastic polyps. Multiple adjustment decreased the strength of the relationships with cluster 2 [corrected] which remained significantly associated with adenomas, but not cancer. CONCLUSION: A lowenergy diet appeared as protective all along the adenoma-carcinoma sequence, contrary to a high-energy, high-processed meat and -animal fat diet.

Adenocarcinoma↗

PubMed2004

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV.

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

Journal Article↗

PubMed2004

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at sqrt[s]=200 GeV.

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.

Journal Article↗

PubMed2004

Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV.

Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

Journal Article↗

PubMed2004

Rho0 production and possible modification in Au+Au and p+p collisions at square root [sNN] = 200 GeV.

We report results on rho(770)(0)-->pi(+)pi(-) production at midrapidity in p+p and peripheral Au+Au collisions at sqrt[s(NN)]=200 GeV. This is the first direct measurement of rho(770)(0)-->pi(+)pi(-) in heavy-ion collisions. The measured rho(0) peak in the invariant mass distribution is shifted by approximately 40 MeV/c(2) in minimum bias p+p interactions and approximately 70 MeV/c(2) in peripheral Au+Au collisions. The rho(0) mass shift is dependent on transverse momentum and multiplicity. The modification of the rho(0) meson mass, width, and shape due to phase space and dynamical effects are discussed.

Journal Article↗

PubMed2004

Azimuthal anisotropy at the relativistic heavy ion collider: the first and fourth harmonics.

We report the first observations of the first harmonic (directed flow, v(1)) and the fourth harmonic (v(4)), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v(2)) generated at RHIC. From the correlation of v(2) with v(1) it is determined that v(2) is positive, or in-plane. The integrated v(4) is about a factor of 10 smaller than v(2). For the sixth (v(6)) and eighth (v(8)) harmonics upper limits on the magnitudes are reported.

Journal Article↗

PubMed2004

Particle-type dependence of azimuthal anisotropy and nuclear modification of particle production in Au+Au collisions at square root of sNN=200 GeV.

We present STAR measurements of the azimuthal anisotropy parameter v(2) and the binary-collision scaled centrality ratio R(CP) for kaons and lambdas (Lambda+Lambda) at midrapidity in Au+Au collisions at square root of s(NN)=200 GeV. In combination, the v(2) and R(CP) particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish p(T) approximately 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K(0)(S) and Lambda+Lambda v(2) values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.

Journal Article↗

PubMed2004

Colorectal adenoma characteristics as predictors of recurrence.

PURPOSE: The identification of groups with a high risk of colorectal adenoma recurrence remains a controversial issue for clinicians. This study was designed to assess the predictive value of initial patient and adenoma characteristics of the three-year recurrence. METHODS: The study population was composed of 552 patients with resected colorectal adenomas who completed the European Fiber-Calcium Intervention trial. At both baseline and three-year examinations, the characteristics of adenomas were recorded according to a standardized protocol. The main outcomes measured were the three-year overall recurrence, recurrence of multiple adenomas, recurrence of advanced adenomas (size > or = 1 cm or tubulovillous/villous architecture or moderate/severe dysplasia), and proximal and distal recurrence. RESULTS: A three-year recurrence was observed in 122 patients (22.1 percent), and more than one-half of them had recurrent adenomas on the proximal colon. After adjustment for patient characteristics and treatment allocation, the number of adenomas and their proximal location at baseline were the main predictors of recurrence. In comparison with patients who had one or two adenomas on the distal colon, patients with three or more adenomas with at least one of them located on the proximal colon had a much higher risk of overall recurrence (5.3; 95 percent confidence interval, 2.7-10.3), proximal recurrence (8.5; 95 percent confidence interval, 4.1-18), and advanced adenoma recurrence (5.5; 95 percent confidence interval, 2.4-12.6). CONCLUSIONS: Follow-up colonoscopies in patients with adenomas should include careful examination of the proximal colon. The time interval between follow-up examinations could probably be extended beyond three years in patients who have only one or two distal adenomas.

Adenoma↗

PubMed2004

Modeling recurrence in colorectal cancer.

OBJECTIVE: To assess the role of recurrence in prognosis of colon cancer, we investigated several methodologic issues, including application of classic survival analysis and Markov model. STUDY DESIGN AND SETTING: The data were recorded by the Registry of Digestive Tumors of Côte d'Or, France, for 874 patients who had been treated by surgery between 1976 and 1984 and followed for up to 11 years. Survival analyses included the Cox proportional hazards model and its two generalizations that allow recurrence to be taken into account as a time-dependent covariate or as a competing outcome. The Markov model was used to analyze simultaneously recurrence and death. RESULTS: The competing risks approach is not appropriate because censoring is indisputably informative. The Markov model and the Cox model, with recurrence as a time-dependent covariate, provided similar results, demonstrating the impact of age and gender on recurrence and revealing a reduction in the effect of site and stage on mortality. CONCLUSION: A Markov multistate model seems to give new insights about the course of digestive cancer progression and into the role of recurrence in this process.

Age Factors↗

PubMed2004

What is the best way to assess microsatellite instability status in colorectal cancer? Study on a population base of 462 colorectal cancers.

The assessment of the microsatellite instability (MSI) status in colorectal cancers is presently warranted for three reasons: 1) as a screening tool for hereditary nonpolyposis colorectal cancer, 2) as a prognostic marker, and 3) as a potential predictive factor of chemotherapy response. The aim of this study was to evaluate, on a large scale with tissue samples coming from a number of different sources, the difficulties met with routine use of immunohistochemistry (IHC) and to determine if it really does offer an accurate alternative to PCR genotyping. Colorectal carcinomas from 462 consecutive patients resected in public or private hospitals were assessed for MSI status by two methods: MSI testing (with BAT-26 microsatellite) and IHC detection of hMLH1, hMSH2, and hMSH6 proteins. Of the 398 cancers tested, immunohistochemistry was noncontributory in 42 (10.5%), focal in 9 (2.3%), and discordant with the PCR results in 36 (9%). For these 87 cases, complementary analyses were performed to explain discrepancy. After additional IHC assay with modified processing protocols, 8 cases remained noncontributory, 2 focal, and 28 discordant: 18 microsatellite stability IHC/MSI PCR and 10 MSI IHC/microsatellite stability PCR. For these discordant cases, we performed a multiplex PCR assay on DNA extracted from the frozen sample and BAT-26 was amplified from DNA extracted from the paraffin blocks used for IHC. Four discordant cases were reclassified after PCR multiplex assay (3 as MSI and 1 as microsatellite stability). Five other cases displayed intratumoral heterogeneity and 19 remained discordant. The discrepancy could be partly explained by variable technical protocols of fixation in the different laboratories, leading to variations in staining quality and difficulties in IHC interpretation. This population-based study is the first one to show that IHC is not sensitive and specific enough to be used routinely. Immunohistochemistry analysis of MMR proteins must be performed in standardized conditions and interpreted by confirmed pathologists. It cannot replace PCR as long as protocols are not optimized and harmonized.

Aged↗

PubMed2004

Public awareness of risk factors and screening for colorectal cancer in Europe.

Colorectal cancer (CRC) is the commonest site for malignancy in Europe. The Commissioner for Health wishes to promote screening for colorectal, breast and cervical cancer in Europe. The aim of this study was to assess public knowledge of CRC in Europe and likely take up of free screening. To this end 20710 members of the public from 21 European countries were interviewed by means of a regular survey amongst consumers (Omnibus survey) using 13 stem questions. Forty-eight per cent thought the population were at equal risk of CRC, only 57% were aware of age and 54% of family history as risk factors. Although 70% were aware of dietary factors, only 30% knew that lack of exercise might be a risk factor. Only 51% had knowledge of CRC screening but 75% were 'very', or 'quite interested, in taking up faecal occult blood (FOB) screening if offered free. Barriers to screening were lack of awareness of risk (31%), youth (22%) and an un-anaesthetic test (19%). There was a big cultural difference in willingness of the public to discuss bowel symptoms: there was a major barrier in Finland (91%), Britain (84%), Luxembourg (82%), Poland (81%) and Portugal (80%); less of a barrier in Spain (49%), Italy (44%) and Iceland (39%). In conclusion, the challenge of achieving high compliance for CRC screening must be a major objective amongst EU member states and non-aligned countries of Europe in the next decade, because it is known that the non-compliant group are those at greatest risk of death from CRC. This study has shown that awareness of CRC is low in Europe and that an educational programme will be essential to achieve high compliance for CRC screening as a means of reducing deaths from bowel cancer.

Adult↗

PubMed2004

Incidence and management of malignant digestive endocrine tumours in a well defined French population.

BACKGROUND AND AIMS: Little is known about the epidemiology of malignant digestive endocrine tumours. The aim of this study was to report on their incidence and management in a well defined population. METHODS: Data were obtained from the population based Digestive Cancer Registry of Burgundy (France) over a 24 year period. Incidence rates were calculated by sex, age groups, and period of diagnosis. Treatment and stage at diagnosis were also investigated. Prognosis was determined using crude and relative survival rates. A multivariate relative survival analysis was performed. RESULTS: Between 1976 and 1999, 229 cases were recorded. Age standardised incidence rates were 0.76/100,000 for men and 0.50/100,000 for women. They increased over time in both sexes. The resectability rate was 74.1%. Among recorded cases, 26.6% did not extend beyond the organ, 20% had lymph node metastases, and 53.3% had visceral metastases or were unresectable. There was no improvement in the resection rate or in the stage at diagnosis over the study period. The overall relative survival rate was 66.9% at one year, 50.4% at five years, and 40.6% at 10 years. Stage at diagnosis, age at diagnosis, and subsite were independent significant prognostic factors. CONCLUSIONS: Although their incidence is increasing, malignant digestive endocrine tumours remain a rare cancer, representing 1% of digestive cancers. Stage at diagnosis and prognosis at a population level are worse than those reported in hospital series. In the short term, new therapeutic possibilities represent the best way to improve their prognosis.

Adolescent↗

PubMed2003

Pion-Kaon correlations in central Au+Au collisions at square root [sNN] = 130 GeV.

Pion-kaon correlation functions are constructed from central Au+Au STAR data taken at sqrt[s(NN)]=130 GeV by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The results suggest that pions and kaons are not emitted at the same average space-time point. Space-momentum correlations, i.e., transverse flow, lead to a space-time emission asymmetry of pions and kaons that is consistent with the data. This result provides new independent evidence that the system created at RHIC undergoes a collective transverse expansion.

Journal Article↗

PubMed2003

Three-pion Hanbury Brown-Twiss correlations in relativistic heavy-ion collisions from the STAR experiment.

Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at sqrt[s(NN)]=130 GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freeze-out. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.

Journal Article↗

PubMed2003

Transverse-momentum and collision-energy dependence of high-pT hadron suppression in Au+Au collisions at ultrarelativistic energies.

We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. A large, approximately constant hadron suppression is observed in central Au+Au collisions for 5<p(T)<12 GeV/c. The collision energy dependence of the yields and the centrality and p(T) dependence of the suppression provide stringent constraints on theoretical models of suppression. Models incorporating initial-state gluon saturation or partonic energy loss in dense matter are largely consistent with observations. We observe no evidence of p(T)-dependent suppression, which may be expected from models incorporating jet attenuation in cold nuclear matter or scattering of fragmentation hadrons.

Journal Article↗

PubMed2003

Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au+Au collisions at RHIC.

We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at sqrt[s(NN)]=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.

Journal Article↗

PubMed2003

Narrowing of the balance function with centrality in Au+Au collisions at the square root of SNN = 130 GeV.

The balance function is a new observable based on the principle that charge is locally conserved when particles are pair produced. Balance functions have been measured for charged particle pairs and identified charged pion pairs in Au+Au collisions at the square root of SNN = 130 GeV at the Relativistic Heavy Ion Collider using STAR. Balance functions for peripheral collisions have widths consistent with model predictions based on a superposition of nucleon-nucleon scattering. Widths in central collisions are smaller, consistent with trends predicted by models incorporating late hadronization.

Journal Article↗

PubMed2003

Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV.

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

Journal Article↗