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Biomedical subjects

C Colin

Publications and source records attributed to C Colin.

At least 19 recordsLinked to original sources

Which screening strategy using BMD measurements would be most cost effective for hip fracture prevention in elderly women? A decision analysis based on a Markov model.

INTRODUCTION: Hip fractures are responsible for excessive mortality, decreasing the 5-year survival rate by about 20%. From an economic perspective, they represent a major source of expense, with direct costs in hospitalization, rehabilitation, and institutionalization. The incidence rate sharply increases after the age of 70, but it can be reduced in women aged 70-80 years by therapeutic interventions. Recent analyses suggest that the most efficient strategy is to implement such interventions in women at the age of 70 years. As several guidelines recommend bone mineral density (BMD) screening of postmenopausal women with clinical risk factors, our objective was to assess the cost-effectiveness of two screening strategies applied to elderly women aged 70 years and older. METHODS: A cost-effectiveness analysis was performed using decision-tree analysis and a Markov model. Two alternative strategies, one measuring BMD of all women, and one measuring BMD only of those having at least one risk factor, were compared with the reference strategy "no screening". Cost-effectiveness ratios were measured as cost per year gained without hip fracture. Most probabilities were based on data observed in EPIDOS, SEMOF and OFELY cohorts. RESULTS: In this model, which is mostly based on observed data, the strategy "screen all" was more cost effective than "screen women at risk." For one woman screened at the age of 70 and followed for 10 years, the incremental (additional) cost-effectiveness ratio of these two strategies compared with the reference was 4,235 euros and 8,290 euros, respectively. CONCLUSION: The results of this model, under the assumptions described in the paper, suggest that in women aged 70-80 years, screening all women with dual-energy X-ray absorptiometry (DXA) would be more effective than no screening or screening only women with at least one risk factor. Cost-effectiveness studies based on decision-analysis trees maybe useful tools for helping decision makers, and further models based on different assumptions should be performed to improve the level of evidence on cost-effectiveness ratios of the usual screening strategies for osteoporosis.

Absorptiometry, Photon↗

Vinflunine: a new active drug for second-line treatment of advanced breast cancer. Results of a phase II and pharmacokinetic study in patients progressing after first-line anthracycline/taxane-based chemotherapy.

To evaluate the single agent activity, pharmacokinetics and tolerability of the novel tubulin targeted agent vinflunine (VFL) (320 mg m(-2) q 21 days) as second-line chemotherapy in patients with metastatic breast carcinoma (MBC). All patients had disease progression after anthracycline/taxane (A/T) therapy. They could have received a nonanthracycline adjuvant treatment and subsequently received a first-line A/T combination for advanced/metastatic disease; or relapsed >6 months after completion of adjuvant A/T therapy and were subsequently treated with the alternative agent; or relapsed within 6 months from an adjuvant A/T combination. Objective response was documented in 18 of 60 patients enrolled (RR: 30% (95% confidence interval (CI): 18.9-43.2%)). Among the responders, seven patients had relapsed during a period of <3 months from taxane-based regimen yielding a RR of 33.3%. The median duration of response was 4.8 months (95% CI: 4.2-7.2), median progression-free survival was 3.7 months (95% CI: 2.8-4.2) and median overall survival was 14.3 months (95% CI: 9.2-19.6). The most frequent adverse event was neutropenia (grade 3 in 28.3% and grade 4 in 36.7% of patients). No febrile neutropenia was observed. Fatigue (grade 3 in 16.7% of patients) and constipation (grade 3 in 11.7% of patients) were also common; these were non-cumulative and manageable permitting achievement of a good relative dose intensity of 93.5%. Vinflunine is an active agent with acceptable tolerance in the management of MBC patients previously treated with (A/T)-based regimens. These encouraging phase II results warrant further investigation of this novel agent in combination with other active agents in this setting or in earlier stages of disease.

Adult↗

Vinflunine -- an active chemotherapy for treatment of advanced non-small-cell lung cancer previously treated with a platinum-based regimen: results of a phase II study.

A multicentre, single-arm, phase II trial designed to determine the efficacy of single-agent vinflunine in patients with advanced non-small-cell lung cancer (NSCLC) previously treated with a platinum-based regimen. The objectives were to assess efficacy in terms of tumour response rate (primary end point), duration of response, progression-free survival (PFS) and overall survival (OS), and to evaluate the toxicity associated with this treatment. Patients with advanced NSCLC with progressive disease having failed prior platinum-based first-line treatment for advanced disease. Five responses out of the 63 treated patients were documented by WHO criteria and validated by an independent panel review (IRP), yielding a response rate of 7.9% (95% CI: 2.6-17.6) in the intent-to-treat analysis and 8.3% (95% CI: 2.8-18.4) in the evaluable population. Disease control was achieved in 35 out of 60 evaluable patients (58.3%). The median duration of response (complete response+partial response), according to modified WHO criteria was 7.8 months (95% CI: 4.6-NR). Median PFS was 2.6 months (95% CI: 1.4-3.8), and the median survival was 7.0 months (95% CI: 5.8-9.2). Grades 3-4 neutropenia was reported in 50% of patients; febrile neutropenia was observed in two patients (3.2%); grades 3-4 myalgia and grade 3 constipation were experienced by 10 (15.9%) and six (9.5%) of patients, respectively. Constipation was manageable, non-cumulative and could be prevented with laxative prophylaxis. The encouraging results from this phase II study with vinflunine warrant further investigations in phase III trials as second- or first-line treatment of advanced non-small-cell lung carcinoma, as a single agent or in combination with other active drugs.

Adult↗

Identification of genes differentially expressed in glioblastoma versus pilocytic astrocytoma using Suppression Subtractive Hybridization.

Glioblastoma (GBM) is a highly malignant glioma, which has the propensity to infiltrate throughout the brain in contrast to pilocytic astrocytoma (PA) of the posterior fossa, which does not spread and can be cured by surgery. We have used Suppression Subtractive Hybridization to define markers that better delineate the molecular basis of brain invasion and distinguish these tumor groups. We have identified 106 genes expressed in PA versus GBM and 80 genes expressed in GBM versus PA. Subsequent analysis identified a subset of 20 transcripts showing a common differential expression pattern for the two groups. GBM differs from PA by the expression of five genes involved in invasion and angiogenesis: fibronectin, osteopontin, chitinase-3-like-1 (YKL-40), keratoepithelin and fibromodulin. PA differs from GBM by the expression of genes related to metabolism (apolipoprotein D), proteolysis (protease-serine-11), receptor and signal transduction (PLEKHB1 for Pleckstrin-Homology-domain-containing-protein-family-B-member-1), transcription/translation (eukaryotic-translation-elongation-factor-1-alpha1) processes and cell adhesion (SPOCK1 for SPARC/Osteonectin-CWCV-kazal-like-domains-proteoglycan). The expression of these genes was confirmed by real-time quantitative RT-PCR and immunohistochemistry. This study highlights the crucial role of brain invasion in GBM and identifies specific molecules involved in this process. In addition, it offers a restricted list of markers that accurately distinguish PA from GBM.

Aged↗

[Evaluation of clinical practices: methods of data collection and information sources?].

OBJECTIVE: The aim of our study is to present the methods used to observe clinical practices, to evaluate their advantages and limits, and to specify the context in which they are preformed. METHODS: We conducted a bibliographical search on MEDLINE using key words, completed by an offline search. We selected articles published in French or English between 1985 and 2003. RESULTS: Thirty articles, of which 3 were reviews, as well as an additional 5 reports and 9 books, were selected. We distinguished direct or objective approaches to clinical practices as well as indirect or declarative approaches. We also noted whether the approach was individual with data collected from individual practitioners, or collective, with data coming from databases. Most methods of collecting data used medical records, often in the context of internal or external clinical audits or peer reviews. The other sources of data were self-administered questionnaires, written case simulations and simulated patients. Data was also extracted from previously existing databases: claims databases, registries and ad hoc databases. CONCLUSION: An objective individual approach insures the highest quality of information, but possible high costs can limit the use of this approach. It is necessary to continue researching the best means of collecting data on clinical practices, because of the obligation of each practitioner to evaluate individual clinical practices.

Data Collection↗

In vitro identification and functional characterization of glial precursor cells in human gliomas.

Human gliomas including astrocytomas and oligodendrogliomas are defined as being composed of neoplastic astrocytes and oligodendrocytes respectively. Here, on the basis of in vitro functional assays, we show that gliomas contain a mixture of glial progenitor cells and their progeny. We have set up explant cultures from pilocytic astrocytomas, glioblastomas and oligodendrogliomas and studied antigens that characterize glial lineage, from the precursor cells (glial restricted precursors and oligodendrocyte-type2-astrocyte/oligodendrocyte precursor cells expressing the A2B5 ganglioside) to the differentiated cells (oligodendrocyte and type-1 and type-2 astrocytes). All tumoral explants contain A2B5+ cells and can generate migrating cells with distinctive functional properties according to glioma subtypes. In pilocytic astrocytomas, very few migrating cells are dividing and can differentiate in type-2 astrocytes or towards the oligodendrocyte lineage. In glioblastomas, most migrating cells are dividing, express A2B5 or glial fibrillary acid protein (GFAP) and can generate oligodendrocytes and type-1 and type-2 astrocytes in appropriate medium. Oligodendroglioma explants are made by actively dividing glial precursor cells expressing A2B5 or PSA-NCAM. Only few cells can migrate and differentiation towards oligodendrocyte lineage does not occur. Isolated A2B5+ cells from both glioblastomas and oligodendrogliomas showed similar genetic alterations as the whole tumour. Therefore, pilocytic astrocytomas contain slowly dividing oligodendrocyte-type2-astrocyte/oligodendrocyte precursor cells in keeping with their benign behaviour whereas both glioblastomas and oligodendrogliomas contain neoplastic glial restricted precursor cells. In oligodendrogliomas, these cells are trapped in undifferentiated and proliferating state. The precursor cells properties present in gliomas give new insight into their histogenesis and open up new avenues for research in the field of gliomagenesis.

Adult↗

Estimates of the number of cancer patients hospitalized in a geographic area using claims data without a unique personal identifier.

OBJECTIVE: In French national claims databases, claims are currently anonymous i.e. not linked to individual patients. In order to improve our estimate of the medical activity related to cancer in one French region, a statistical method was developed to use claims data to assess the number of cancer patients hospitalized in acute care. METHODS: This method used the medical and administrative information available in the claims (i.e. age, primary site, length of stay) to predict an average number of stays per patient, followed by a number of patients. It was based on a two-phase study design using an internal dataset which contained personal identifiers to estimate the model parameters. RESULTS: The predicted number of acute care patients hospitalized in one or several health care centers in one French region was 38,109 with a 95% predictive interval (37,990; 38,228) for the first six months of 2002. A prediction error of 24 per thousand was found. CONCLUSION: We provide a good estimate of the morbidity in acute care hospitals using claims data that is not linked to individual patients. This estimate reflects the medical activity and can be used to anticipate acute care needs.

Adolescent↗

[Role of gynecologists in the care of women with breast cancer].

OBJECTIVES: To describe the role of gynecologists in the care of women with breast cancer, their relationship with hospital specialists and with patients, and their expectations in terms of the quality of this relationship. MATERIALS AND METHODS: A descriptive cross-sectional study was performed in 2002. Two hundred and fifty gynecologists from Rhone Alpes region were randomly selected and received a questionnaire. RESULTS: Sixty-four percent of the polled practitioners answered. Forty-two percent of gynecologists had about 25-50 patients with breast cancer. Their participation in the care principally concerned the phases of diagnosis (99%) and remission (98.5%). Eight percent took part in therapeutic decision making. Ninety-two percent of the gynecologists wanted to receive systematically feedback concerning any consultation or hospitalization and 98% wanted to know the name and address details of the care coordinator. CONCLUSION: Gynecologists are willing to participate in the care of breast cancer patients. This for, they want to have more details about therapy, follow-up and the level of information given to the patients.

Breast Neoplasms↗

Phase II trial of oral vinorelbine in combination with cisplatin followed by consolidation therapy with oral vinorelbine in advanced NSCLC.

BACKGROUND: Among the cytotoxic agents commonly combined with cisplatin in the treatment of advanced NSCLC, vinorelbine has led to significant outcome improvements. Adding more than four cycles of the combination regimen increase toxicities. The availability of an oral form of vinorelbine appeared as a particularly convenient way to provide a consolidation treatment to patients who have achieved an objective response or stable disease. PATIENTS AND METHODS: This multi-centre phase II open-label, non-comparative study was designed to evaluate the treatment with four cycles of the combination chemotherapy with oral vinorelbine at the dose of 60 mg/m2 on day 1 and day 8 for the first cycle and then 80 mg/m2 plus cisplatin 80 mg/m2 on day 1 every 3 weeks followed for patients with objective response or stable disease by consolidation therapy with oral vinorelbine at 80 mg/m2 weekly on patients with unresectable localised or metastatic non-small-cell lung cancer (NSCLC). The primary endpoint was tumor response. The secondary objectives were progression free-survival, overall survival and toxicity assessment. Visual analogue scales (VAS) filled by the patients were also used to evaluate subjective changes under treatment, reflecting patients' clinical benefit. RESULTS: Fifty-six patients enrolled into the study from April 2001 to April 2002 received the combination regimen. Twenty-five patients (43.9%) also received the subsequent consolidation treatment. Partial tumor responses were obtained in 13 patients (26.5%, 95% CI 15.0-41.1) of 49 evaluable patients. Stable disease was observed in 22 (44.9%) of patients. The median duration of response was 6 months (95% CI 4.3-8.2). The median progression free-survival was 4.2 months (95% CI 2.8-6). The median overall survival time was 10 months (95% CI 7.4-14) and the 1 year survival was 42.6%. The main toxicities recorded were haematological. Grade 3 and 4 neutropenia were observed in 16 patients (29.1%). Nausea, vomiting and fatigue were the major non-haematological toxicities reported. Among the symptoms recorded by the patients on VAS scales (appetite, fatigue, pain, cough, dyspnea, haemoptysis), except anorexia, all symptoms were improved during the combination therapy and in the consolidation phase. CONCLUSION: This study confirms that the efficacy of the cisplatin/oral vinorelbine combination in NSCLC is comparable to cisplatin/I.V. vinorelbine. This study also suggests that consolidation therapy with vinorelbine alone may probably prolong the efficacy of the combination regimen. The convenience offered to patients by an oral form of vinorelbine is a definite asset for consolidation therapy.

Administration, Oral↗

Generalization of the generation of an MMN by illusory McGurk percepts: voiceless consonants.

OBJECTIVE: The existence of a Mismatch Negativity (MMN) evoked by McGurk percepts elicited by audiovisual syllables with constant auditory components has been previously demonstrated with voiced consonants [Clin. Neurophysiol. 113 (2002) 495]. The present study aimed at generalizing such results with voiceless consonants. In a first experiment, the MMN was computed using the classical subtraction method (standard minus deviant). Since results showed a possible contamination by exogenous visual components, a technique preventing from including those components in the differential waveform was used in a second experiment (deviant in sequence minus deviant presented alone). METHODS: Cortical evoked potentials were recorded using the oddball paradigm on eight adults in three experimental conditions (auditory alone, visual alone and audiovisual) for experiment one and in two conditions (visual alone and audiovisual) for experiment two. Obtaining illusory percepts was confirmed in additional psychophysical experiments. RESULTS: Significant MMNs were recorded in the three conditions of experiment one, whereas only the audiovisual condition of experiment two gave rise to a significant MMN. CONCLUSIONS: Provided that the MMN is computed with deviant stimuli only, the present results confirm the elicitation of genuine audiovisual MMN. Possible refractoriness effects and N2b confound have, however, to be controlled for in further studies.

Adolescent↗

Extended lower limb venous ultrasound for the diagnosis of proximal and distal vein thrombosis in asymptomatic patients after total hip replacement.

OBJECTIVE: To assess the performance of extended lower limb venous ultrasound (US) for the diagnosis of asymptomatic deep vein thrombosis (DVT) and to estimate a 3-month DVT incidence on repeated US after total hip replacement. DESIGN: Diagnostic performance study and prospective cohort study. MATERIALS AND METHODS: US was compared to phlebography in 70 consecutive patients and interobserver agreement was assessed in the last 48 patients at day 8. US was repeated in these 48 patients at day 13 and day 90. RESULTS: Phlebography demonstrated a DVT in 18/70 (26%) patients, with five proximal and 13 distal and US in 23/70 (33%) patients, with eight proximal and 15 distal. Sensitivity and specificity of US with 95% CI were 94% (73-100) and 89% (76-96), respectively. Sensitivity in isolated distal vein thrombosis was 92% (67-99). The Kappa coefficient for agreement between observers was 0.84 (0.66-1.00). Follow-up showed a DVT in 15/48 (31%) patients on day 8, in 20/48 patients (42%) on day 13. DVT recurred in two patients during follow-up. CONCLUSIONS: The incidence of asymptomatic DVT is still significant despite prophylaxis but most DVTs remain distal and occur in the first 2 weeks. Extended US could replace phlebography for systematic screening in clinical trials using surrogate endpoints in view of its high accuracy and reliability.

Arthroplasty, Replacement, Hip↗

[Sensitivity and specificity of two methods used to identify incident breast cancer in specialized units using claims databases].

BACKGROUND: Hospital claims databases from acute care units are available nationwide and contain most patients at the beginning of their cancer. The goal is to define the ability of these databases to provide a number of incident breast cancer cases using identification methods. Two identification methods were assessed in three specialized sections of a teaching hospital. METHODS: The first method identified women who had at least one stay with a principal diagnosis of breast cancer. The second, which is more restrictive, identified women who had at least one stay with a principal diagnosis of breast cancer and a breast cancer-specific surgical treatment code. Both methods were applied to 4588 women 20 Years of age or older hospitalized in three specialized sections of the Hospices Civils de Lyon in 2000. To categorize these women in two groups, incident breast cancer cases or non-incident breast cancer cases, 150 women were randomized in each of two groups, one for incident breast cancer cases and one for non-incident breast cancer cases. Their medical records were used as references. RESULTS: Sensitivity, specificity and their credibility intervals were respectively 99.4% (84-99.9) and 91.7% (90.3-93.3) for the first method and 93.8% (76.2-98.7) and 97.3% (96.1-98) for the second. Among women wrongly identified with an incident breast cancer in 2000, 75.4% (43/57) had a breast cancer that was not incident that Year with the first method, compared to 96% (24/25) with the second. Among these women wrongly identified with an incident breast cancer, coding errors of the principal diagnosis were found for 24.6% (14/57) of patients with the first method and for 4% (1/25) with the second. Their correction led to 99.2% (86.5-99.9) sensitivity and 92.9% (91.4-94.6) specificity for the first method and to 94.2% (76.5-98.7) sensitivity and 97.3% (96.2-98.1) specificity for the second. CONCLUSIONS: The second method using cancer-specific surgical codes appeared more specific with a slight loss in sensitivity. The use of identification methods to assess the number of incident cancer cases still have to be defined.

Adult↗

[Public health in Quebec at the dawn of the 21st century].

This paper summarises the status of public health in Quebec at the dawn of the 21st century. After introducing the current definition, the author lays out five basic functions of public health in Quebec: knowledge and surveillance of populations health and wellbeing, health protection; prevention of disease, trauma and social problems that influence health; health and wellbeing promotion; and service organization and evaluation. The organization of public health services is then described at the local level (CLSC), regional level (Public health units) and national level (Ministry, Public health directorate and National Institute of Public Health). Finally, the trends and priorities elaborated over the last ten years, as well as the National Public Health Program to be implemented over the next ten years are described.

Forecasting↗

[Public health nurses in Quebec: an essential contribution that remains to be known].

Public health nurses in Quebec are essential although little is known about their role. Generally trained at the undergraduate level, with additional qualifications in community health, they essentially work in CLSCs in maternal and child health programs, youth clinics or occupational health. In regional public health departments, they also work in the field of infectious disease prevention or other programs. Like their colleagues, they are confronted to the profession's challenges, the most notable being current and future shortage of nurses. However, they can now count on a new. As nurses further develop their practice and orient it even more towards primary prevention and health promotion, they will significantly contribute to the National Public Health Program and to the improvement of population health and wellbeing.

Health Promotion↗

[Hormone replacement therapy after breast cancer. Yes...or no?].

Clinical and experimental studies indicate that combined unique conjugated estrogens and medroxyprogesterone acetate moderately increase the risk of breast cancer in postmenopausal women. Classically, hormone replacement therapy is contra-indicated in women with a past history of breast cancer due to the fear of recurrence. However, these postmenopausal patients complain about hot flushes and adjuvant hormonal therapies (such as aromatase inhibitors, SERMs and Tamoxifen...) aggravate their symptoms. Observational studies and their meta-analyses do not show a deleterious effect but rather a beneficial impact of hormone replacement therapy among women with a past history of breast cancer. We summarise all these studies and their biological, clinical and epidemiological interpretations. We conclude that short term hormone replacement therapy is safe among those women requesting a replacement therapy after complete information. It is however advisable to conclude definitely only when prospective randomised trials with estradiol or tibolone (a promising alternative) will be available. Such ongoing studies will allow to conclude definitely the possible benefits and risks of hormone replacement therapy among patients with a past history of breast cancer.

Breast Neoplasms↗

[Benefits and limitations of mammography].

The literature on screening mammography provides ample opportunity for doubt (the sceptics) and dogma (the screening zealots), and can be interpreted to prove both benefit and harm. The benefit of mammography screening, if any, is modest and the balance between beneficial (potentially, a 20% relative reduction in breast cancer mortality with no significant benefit on all-cause mortality) and harmful (physical and psychological morbidity related to the 15-40% missed cancers and the 80-90% false-positive diagnoses) effects is still delicate. The mammogram alone is a modest weapon. Concurrent clinical breast examination is mandatory. Women that are concerned about breast cancer should be fully informed of the potential benefits and risks of screening mammography. These women should benefit from mammography with concurrent clinical breast examination, and possible whole-breast ultrasound in heterogeneously dense and extremely dense breast patterns.

Age Factors↗