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Biomedical subjects

M Buyse

Publications and source records attributed to M Buyse.

At least 127 records · Page 7Linked to original sources
PubMed1977

Growth abnormalities in genetic syndromes.

The presence of a growth abnormality may be documented by determination of growth velocity, calculation of the upper segment/lower segment ratio or the AF/AT ratio, and measurement of head circumference. Important considerations in differential diagnosis of specific malformation syndromes are birth weight, limb and truck alterations, head size, physical features, and presence or absence of mental retardation. Additional clinical measurements, such as measurement of chest circumference and of finger and hand length, may be useful in selected cases. These data, combined with historical information, can indicate a specific diagnosis and facilitate the choice of confirmatory laboratory studies.

Anthropometry↗
PubMedDate not supplied

Issues of efficiency in combining proportions of deaths from several clinical trials.

The Mantel-Haenszel test provides a straightforward method to combine results from several clinical trials when only summary information, such as the proportion of deaths, is available for each trial. More efficient tests, such as the stratified logrank test, should be used if the survival and censoring times are known for all individuals, but in practice, the cost and effort of obtaining this information may be prohibitive. The purpose of this paper is to derive a general expression for the asymptotic relative efficiency (ARE) of the Mantel-Haenszel test with respect to the stratified logrank test, and to compute the ARE in situations which are likely to be of practical interest. The results show that under realistic assumptions about the survival distribution, losses to follow-up and duration of accrual, the ARE frequently exceeds 80 per cent. An example is given to show the usefulness of the approach when combining proportions of deaths from several cancer clinical trials.

Clinical Trials as Topic↗
PubMedDate not supplied

Cellular vaccines.

This project is devoted to the development of novel cellular vaccines designed to treat cancer patients. These cellular vaccines present and enhance immunogens, which will elicit a potent immune response. The goal is to achieve safe and effective immune reaction against the patient's own tumour. (1) Autologous cellular vaccines are prepared by processing circulating blood mononuclear cells outside of the patient's body (ex vivo) to differentiate them into antigen-presenting cells (APCs). Monocyte-derived APCs (MD-APCs) are then grown in the presence of exogenous target antigens (tumour cell debris, or apoptotic bodies) to become fully mature APCs. (2) Functionality for antigen presentation to T cells of ex vivo MD-APCs is evaluated in vivo. (3) Cellular vaccines are tested in selected rodent animal models. Efficiency and immune response are monitored in pertinent experimental systems for cancer. Pharmacological data are generated for clinical investigation. Tolerance and biologic effects are documented in primates. (4) The first clinical trials on cancer patients are taking place in 1998 on melanoma and prostate cancer to validate the concept. Specialized cell processors with dedicated software and standardized controls are being developed and used for the preparation of cellular vaccines. (5) The evaluation of new non-viral vectors and the validation of new non-viral transfection methods of mononuclear cells with marker genes is in progress and will lead to the ex vivo transfection of genes coding for immunostimulating cytokines or for tumour antigens in MD-APCs. Efficiency will be validated in vitro and in animal models. The ex vivo and animal model studies validate the clinical relevance of this new cellular immunotechnology. Clinical validation of individual autologous cellular vaccines in specific indications for which no treatment is presently available will allow the development of cellular and gene immunotherapy for other types of cancers.

Animals↗
PubMedDate not supplied

[The problem of therapeutic efficacy indices. 1. Elements of the problem].

Efficacy indices measure the efficacy of therapies. They derive, by definition, from two quantities, the basal or control risk of event, Rc, observed in the control group, and the on-treatment risk, Rt, observed in the treated group. In clinical trials and meta-analyses, each is an unbiased measure of efficacy. Although they are a combination of frequencies, these indices are used in clinical practice to predict the benefit in treated patients. Their relevance to express efficacy depends on the type of clinical condition, and is better for acute diseases than for chronic diseases. In order to be useful for prescribers, they should meet certain specifications. In addition, they should be considered in the more general framework of effect models.

Clinical Trials as Topic↗
PubMedDate not supplied

[The problem of therapeutic efficacy indices. 2. Description of the indices].

The four indices for a binary outcome or therapeutic objective are: the odds ratio, the relative risk, the absolute benefit and the number of patients to treat. For a continuous outcome, the effect size is the best choice. The odds ratio approximates the relative risk. The difference may be large in some instances. The number of patients to treat is the reciprocal of the absolute benefit. Although they are built on the same two quantities, they are not interchangeable and should not be considered in the same way. Moreover, their meaning is not straightforward and they can be misused.

Clinical Protocols↗
PubMedDate not supplied

[Outline of the problem of indices of therapeutic efficacy. 4. Expression of efficacy when the underlying illness is incurable. Study Group for the Indices of Efficacy].

In chronic illness, when death or a non-fatal event can occur at any time, the current efficacy indices are no longer appropriate to express the effect of the treatment on the potential therapeutic objectives. The inappropriateness is not dependent on the effect model. Clues for solutions are proposed.

Chronic Disease↗
PubMedDate not supplied

[The problem of therapeutic efficacy indices. 3. Comparison of the indices and their use].

Efficacy indices do not contain the same information although they are all combinations of the same two quantities. Therefore, one should choose the proper index. Actually, none is entirely appropriate. Each more or less meets the specifications, depending on the underlying effect model for the therapy considered. However, one can say that the absolute benefit is more appropriate from the patient's point of view, the relative from the scientific point of view and the number of patients to treat from the policy maker's point of view. Nevertheless, this classification needs to be considered with caution. Finally, it emerges from the review that none is fully relevant to express the efficacy of a therapy, even in the most suitable condition, the acute illness.

Drug Evaluation↗
PubMedDate not supplied

Adjuvant FAM2 in resectable gastric cancer.

In spite of the improvements in surgical techniques and intensive care, no important benefit in the prognosis of patients with gastric carcinoma has been attained in the last twenty years. Different adjuvant treatment protocols have been proposed in an attempt to improve upon the results obtained with surgery only. In western countries, the FAM chemotherapeutic regimen is one on the most widely used for the treatment of advanced gastric carcinoma. In 1982 the G.I. GROUP of the EORTC proposed a modification (FAM2) to the original FAM as an adjuvant treatment in a controlled clinical study for gastric carcinoma. It is still too early to determine any therapeutic advantages of FAM2 in this protocol. Although the FAM2 regimen is fairly well tolerated, there is some toxicity which, however, seems to be slightly higher than in the regular FAM. It remains to be seen if this is a reasonable price to pay for still unknown therapeutic advantages. In view of the scarcity of available data in this field and the conflicting results which have emerged so far, the results of our study are awaited with great interest.

Adenocarcinoma↗
PubMedDate not supplied

Adjuvant therapy in colorectal cancer.

While uncontrolled and retrospective studies suggest a treatment benefit for radiotherapy or chemotherapy when administered as adjuvant before or after surgical resection with a curative aim for colon cancer, prospective randomized clinicals trials failed to show any advantage and do not to date confirm the efficiency of the proposed adjuvant therapy. For rectal cancer, preoperative irradiation administered at the dose of 34.5 Gy and postoperative radiotherapy administered at the dose of 46 to 53 Gy markedly decreased the local recurrence rate, however, these treatments failed to improve the 5 year survival rate significantly. Recently the efficacy of a postoperative chemotherapy was observed in a randomized clinical trial. The administration of methyl-CCNU, Vincristine and 5-fluorouracil after surgical resection of rectal cancer improved both the disease-free survival and the survival rate. Another randomized study showed a benefit of combined post-operative radiotherapy and chemotherapy with methyl-CCNU and 5-FU. Advantages and disadvantages of preoperative irradiation treatment and postoperative irradiation treatment are discussed.

Antineoplastic Agents↗