Impact of therapeutic research on informed consent and the ethics of clinical trials: a medical oncology perspective.
(1/960)
PURPOSE: To create a more meaningful understanding of the informed consent process as it has come to be practiced and regulated in clinical trials, this discussion uses the experience gained from the conduct of therapeutic research that involves cancer patients. DESIGN: After an introduction of the ethical tenets of the consent process in clinical research that involves potentially vulnerable patients as research subjects, background that details the use of written consent documents and of the term "informed consent" is provided. Studies from the cancer setting that examine the inadequacies of written consent documents, and the outcome of the consent process itself, are reviewed. Two ethically challenging areas of cancer clinical research, the phase I trial and the randomized controlled trial, are discussed briefly as a means of highlighting many dilemmas present in clinical trials. Before concluding, areas for future research are discussed. RESULTS: Through an exclusive cancer research perspective, many current deficiencies in the informed consent process for therapeutic clinical trials can be critically examined. Also, new directions for improvements and areas of further research can be outlined and discussed objectively. The goals of such improvements and research should be prevention of further misguided or ineffective efforts to regulate the informed consent process. CONCLUSION: To ignore this rich and interesting perspective potentially contributes to continued misunderstanding and apathy toward fulfilling the regulatory and ethically obligatory requirements involved in an essential communication process between a clinician-investigator and a potentially vulnerable patient who is considering clinical trial participation. (+info)
The utilization of cytokines in stem cell mobilization strategies.
(2/960)
High-dose myeloablative chemotherapy supported by peripheral blood progenitor cell (PBPC) transplant is rapidly replacing bone marrow transplant to treat a number of chemosensitive cancers. Numerous investigators have studied the relationship of CD34+ cell dose and engraftment kinetics in an effort to help define minimum and optimum target stem cell doses. A number of studies suggest that reinfusion of > or = 5 x 10(6) CD34+ PBPCs results in prompt and durable platelet engraftment. Mobilization of stem cells can be accomplished through use of chemotherapy alone, colony-stimulating factors, or a combination of the two. Strategies to improve PBPC yields include filgrastim in combination with chemotherapy or with other hematopoietic growth factors. In this paper, the advantages and disadvantages of these strategies will be discussed, and the results of a recently conducted, randomized, controlled phase 3 clinical trial in breast cancer patients receiving either SCF plus filgrastim or filgrastim alone for PBPC mobilization will be reviewed. (+info)
Incremental costs of enrolling cancer patients in clinical trials: a population-based study.
(3/960)
BACKGROUND: Payment for care provided as part of clinical research has become less predictable as a result of managed care. Because little is known at present about how entry into cancer trials affects the cost of care for cancer patients, we conducted a matched case-control comparison of the incremental medical costs attributable to participation in cancer treatment trials. METHODS: Case patients were residents of Olmsted County, MN, who entered phase II or phase III cancer treatment trials at the Mayo Clinic from 1988 through 1994. Control patients were patients who did not enter trials but who were eligible on the basis of tumor registry matching and medical record review. Sixty-one matched pairs were followed for up to 5 years after the date of trial entry for case patients or from an equivalent date for control patients. Hospital, physician, and ancillary service costs were estimated from a population-based cost database developed at the Mayo Clinic. RESULTS: Trial enrollees incurred modestly (no more than 10%) higher costs over various follow-up periods. The mean cumulative 5-year cost in 1995 inflation-adjusted U.S. dollars among trial enrollees after adjustment for censoring was $46424 compared with $44 133 for control patients. After 1 year, trial enrollee costs were $24645 compared with $23 964 for control patients. CONCLUSIONS: This study suggests that cancer chemotherapy trials may not imply budget-breaking costs. Cancer itself is a high-cost illness. Clinical protocols may add relatively little to that cost. (+info)
Safety and tolerability of fluconazole in children.
(4/960)
The safety profile of fluconazole was assessed for 562 children (ages, 0 to 17 years) comprising 323 males and 239 females. The data are derived from 12 clinical studies of fluconazole as prophylaxis or treatment for a variety of fungal infections in predominantly immunocompromised patients. Most children received multiple doses of fluconazole in the range of 1 to 12 mg/kg of body weight; a few received single doses. Administration was mainly by oral suspension or intravenous injection. Overall, 58 (10.3%) children reported 80 treatment-related side effects. The most common side effects were associated with the gastrointestinal tract (7.7%) or skin (1.2%). Self-limiting, treatment-related side effects affecting the liver and biliary system were reported in three patients (0.5%). Overall, 18 patients (3.2%) discontinued treatment due to side effects, mainly gastrointestinal symptoms. Dose and age did not appear to influence the incidence and pattern of side effects. Treatment-related laboratory abnormalities were uncommon, the most frequent being transient elevated alanine aminotransferase (4.9%), aspartate aminotransferase (2.7%), and alkaline phosphatase (2.3%) levels. Although 98.6% of patients were taking concomitant medications, no clinical or laboratory interactions were observed. The safety profile of fluconazole was compared with those of other antifungal agents, mostly oral polyenes, by using a subset of data from five controlled studies. Side effects were reported by more patients treated with fluconazole (45 of 382; 11.8%) than by those patients treated with comparable agents (25 of 381; 6.6%); vomiting and diarrhea were the most common events in both groups. The incidence and type of treatment-related laboratory abnormalities were similar for the two groups. In conclusion, fluconazole was well tolerated by the pediatric population, many of whom were suffering from severe underlying disease and were taking a variety of concurrent medications. The safety profile of fluconazole in children mirrors the excellent safety profile seen in adults. (+info)
Use of the Barthel index and modified Rankin scale in acute stroke trials.
(5/960)
BACKGROUND AND PURPOSE: The Barthel Index (BI) and the Modified Rankin Scale (MRS) are commonly used scales that measure disability or dependence in activities of daily living in stroke victims. The objective of this study was to investigate how these scales were used and interpreted in acute stroke trials. METHODS: We identified from MEDLINE the major efficacy trials with neuroprotective drugs, thrombolytic drugs, and anticoagulants in acute ischemic stroke published between January 1995 and December 1998. We selected those trials that used the BI and/or MRS as outcome parameters. RESULTS: Fifteen trials fulfilling the inclusion criteria were identified. The BI was used in 13 and the MRS in 8. In 4 trials mean and median scores of the BI were used, and in 1 trial median scores of the MRS were compared. Primary end points included the BI in 7, the MRS in 6, and both the BI and MRS in 3. With regard to the BI, a variety of sum scores between 50 and 95 were used as cutoff scores to define favorable outcome. Favorable outcome on the MRS was defined as either 3, or BI <60. (+info)
Simulation studies of phase III clinical trials to test the efficacy of a candidate HIV-1 vaccine.
(6/960)
One question of particular importance in phase III HIV vaccine trials is the choice of efficacy measure (EM) to validly and precisely estimate the true vaccinal efficacy. Traditional EMs, based on hazard rate ratio (HRR) or cumulative incidence ratio (CIR) are time-sensitive to mode of vaccine action and population heterogeneities. Through Monte-Carlo simulation, the performance of HRR and CIR based EMs are examined across different trial designs and vaccine and population characteristics. A new EM based on log-spline hazard regression (HARE) is proposed. Given that vaccinal properties (mode of action, time-lag, waning) are unknown a priori, appropriate selection of EM is problematic, and HRR and CIR can be unreliable to estimate the true maximum efficacy of candidate products. Non-random sexual mixing can exacerbate biases in HRR and CIR. HARE can offer valid estimation across different modes of vaccine action and in presence of frailty effects, contrary to its traditional counterparts. Our simulation studies highlight the weaknesses of widely used EMs while offering guidelines for trial design and suggesting new avenues for statistical analysis. (+info)
Twenty years of phase III trials for patients with extensive-stage small-cell lung cancer: perceptible progress.
(7/960)
PURPOSE: All cooperative group studies performed in North America for patients with extensive-stage small-cell lung cancer (SCLC) were evaluated to determine the pattern of the clinical trials and the outcome of patients over the past 20 years. PATIENTS AND METHODS: Phase III trials for patients with extensive-stage SCLC were identified through a search of the National Cancer Institute Cancer Therapy Evaluation Program database from 1972 to 1993. Patients with extensive-stage SCLC treated during a similar time interval listed in the Surveillance, Epidemiology, and End Results (SEER) database were also examined. Trends were tested in the number of trials over time, the number and sex of patients entered onto the trials, and the survival time of patients treated over time. RESULTS: Twenty-one phase III trials for patients with extensive-stage SCLC were initiated between 1972 and 1990. The median of the median survival times of patients treated on the control arms of the phase III trials initiated between 1972 and 1981 was 7.0 months; for those patients enrolled onto control arms between 1982 and 1990, the median survival time was 8.9 months (P =.001). Analysis of the SEER database of patients with extensive-stage SCLC over the same time period shows a similar 2-month prolongation in median survival time. CONCLUSION: Analysis of 21 phase III trials initiated in North America and the SEER database from 1972 to 1994 demonstrates that there has been a modest improvement in the survival time of patients with extensive-stage SCLC. (+info)
Low-grade stage III-IV follicular lymphoma: multivariate analysis of prognostic factors in 484 patients--a study of the groupe d'Etude des lymphomes de l'Adulte.
(8/960)
PURPOSE: To identify the prognostic factors that influence overall survival (OS) in patients with stage III-IV follicular lymphomas and evaluate the clinical usefulness and the prognostic value of the International Prognostic Index (IPI). PATIENTS AND METHODS: Four hundred eighty-four patients with Ann Arbor stage III-IV follicular lymphomas treated in two phase III trials from 1986 to 1995 were screened for this study. All histologic slides were reviewed by two hematopathologists. The influence of the initial parameters on survival was defined by univariate (log-rank test) and multivariate (Cox model) analyses. RESULTS: The poor prognostic factors for OS (age > 60 years, "B" symptom(s), > or = two extranodal sites, stage IV disease, tumor bulk > 7 cm, at least three nodal sites > 3 cm, liver involvement, serous effusion-compression or orbital/epidural involvement, and erythrocyte sedimentation rate > 30 mm/h) that were significant in univariate analysis were subjected to multivariate analysis. Three factors remained significant: B symptom(s) (risk ratio = 1.80), age greater than 60 years (risk ratio = 1.60), and at least three nodal sites greater than 3 cm (risk ratio = 1.71). When the IPI was applied to these patients, the score was 1, 2, 3, and 4-5 in 49%, 39%, 11%, and 2%, respectively, and it was significant for progression-free survival (P =.002) and OS (P =.0001). CONCLUSION: Three prognostic factors for poor OS were identified: B symptoms, age greater than 60 years, and at least three nodal sites greater than 3 cm. The IPI was prognostic for OS, but in this population, a very low number of patients belonged to the high-risk groups. (+info)