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Mead GM, Russell M, Clark P, Harland SJ, Harper PG, Cowan R, Roberts JT, Uscinska BM, Griffiths GO, Parmar MK. A randomized trial comparing methotrexate and vinblastine (MV) with cisplatin, methotrexate and vinblastine (CMV) in advanced transitional cell carcinoma: results and a report on prognostic factors in a Medical Research Council study. MRC Advanced Bladder Cancer Working Party. Br J Cancer 1998; 78:1067-75. [PMID: 9792152 PMCID: PMC2063167 DOI: 10.1038/bjc.1998.629] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transitional cell carcinomas may arise at any site within the urinary tract and are a source of considerable morbidity and mortality. In particular, patients with metastatic disease have a poor prognosis, with less than 5% alive at 5 years. A multicentre randomized trial comparing methotrexate and vinblastine (MV) with cisplatin, methotrexate and vinblastine (CMV) in advanced or metastatic transitional cell carcinoma was conducted in the UK. From April 1991 to June 1995, 214 patients were entered by 16 centres, 108 randomized to CMV and 106 to MV. A total of 204 patients have died. The hazard ratio (relative risk of dying) was 0.68 (95% CI 0.51-0.90, P-value = 0.0065) in favour of CMV. This translates to an absolute improvement in 1-year survival of 13%, 16% in MV and 29% in CMV. The median survival for CMV and MV was 7 months and 4.5 months respectively. Two hundred and eight patients objectively progressed or died. The hazard ratio was 0.55 (95% CI 0.41-0.73, P-value = 0.0001) in favour of CMV. Two hundred and nine patients symptomatically progressed or died. The hazard ratio was 0.48 (95% CI 0.36-0.64, P-value = 0.0001) in favour of CMV. The most important pretreatment factors influencing overall survival were WHO performance status and extent of disease. These two factors were used to derive a prognostic index which could be used to categorize patients into three prognostic groups. We conclude that the addition of cisplatin to methotrexate and vinblastine should be considered in patients with transitional cell carcinoma, taking into account the increased toxicity.
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Bailey AJ, Parmar MK, Stephens RJ. Patient-reported short-term and long-term physical and psychologic symptoms: results of the continuous hyperfractionated accelerated [correction of acclerated] radiotherapy (CHART) randomized trial in non-small-cell lung cancer. CHART Steering Committee. J Clin Oncol 1998; 16:3082-93. [PMID: 9738579 DOI: 10.1200/jco.1998.16.9.3082] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The randomized multicenter trial of continuous hyperfractionated accelerated radiotherapy (CHART) versus conventional radiotherapy for patients with non-small-cell lung cancer (NSCLC) showed a significant survival benefit to CHART (29% v 20% at 2 years, P=.004). However, an assessment of the effect on physical and psychologic symptoms is vital to balance the costs and benefits of the two treatments. METHODS A total of 356 patients in the United Kingdom completed the Rotterdam Symptom Checklist (RSCL) and the Hospital Anxiety and Depression Scale (HADS) at 10 time points. The principal aim of the analyses was to keep the methods simple, so as to allow the presentation and interpretation of the results to be as clear as possible. This was achieved by (1) considering individual symptoms rather than symptom subscales or domains, (2) assessing short-term effects (up to 3 months) and long-term effects (at 1 and 2 years) separately, and (3) for the short-term analyses, (a) splitting the data randomly into an exploratory data set and a confirmatory data set, and (b) using two different methods of analysis: a subject-specific approach, which used the area under the curve (AUC) as a summary measure, and a group-based method, which plotted the percent of patients with moderate or severe symptoms over time. RESULTS The results indicate that apart from CHART causing transient pain on swallowing and heartburn, there was little difference between the regimens in the short or long-term. CONCLUSION Combining the results of the patient-assessed symptom comparisons with the clinical results indicates that CHART confers a major benefit without serious morbidity.
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Arnott SJ, Duncan W, Gignoux M, Girling DJ, Hansen HS, Launois B, Nygaard K, Parmar MK, Roussel A, Spiliopoulos G, Stewart LA, Tierney JF, Mei W, Rugang Z. Preoperative radiotherapy in esophageal carcinoma: a meta-analysis using individual patient data (Oesophageal Cancer Collaborative Group). Int J Radiat Oncol Biol Phys 1998; 41:579-83. [PMID: 9635705 DOI: 10.1016/s0360-3016(97)00569-5] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The existing randomized evidence has failed to conclusively demonstrate the benefit or otherwise of preoperative radiotherapy in treating patients with potentially resectable esophageal carcinoma. This meta-analysis aimed to assess whether there is benefit from adding radiotherapy prior to surgery. METHODS AND MATERIALS This quantitative meta-analysis included updated individual patient data from all properly randomized trials (published or unpublished) comprising 1147 patients (971 deaths) from five randomized trials. RESULTS With a median follow-up of 9 years, the hazard ratio (HR) of 0.89 (95% CI 0.78-1.01) suggests an overall reduction in the risk of death of 11% and an absolute survival benefit of 3% at 2 years and 4% at 5 years. This result is not conventionally statistically significant (p = 0.062). No clear differences in the size of the effect by sex, age, or tumor location were apparent. CONCLUSION Based on existing trials, there was no clear evidence that preoperative radiotherapy improves the survival of patients with potentially resectable esophageal cancer. These results indicate that if such preoperative radiotherapy regimens do improve survival, then the effect is likely to be modest with an absolute improvement in survival of around 3 to 4%. Trials or a meta-analysis of around 2000 patients would be needed to reliably detect such an improvement (15-->20%).
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Stewart LA, Parmar MK, Tierney JF. Meta-analyses and large randomized, controlled trials. N Engl J Med 1998; 338:61; author reply 61-2. [PMID: 9424569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Hopwood P, Harvey A, Davies J, Stephens RJ, Girling DJ, Gibson D, Parmar MK. Survey of the Administration of quality of life (QL) questionnaires in three multicentre randomised trials in cancer. The Medical Research Council Lung Cancer Working Party the CHART Steering Committee. Eur J Cancer 1998; 34:49-57. [PMID: 9624237 DOI: 10.1016/s0959-8049(97)00347-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We surveyed centres collaborating in two trials in lung cancer (LU12, LU13) and one in lung and head and neck cancer (CHART) to find out how QL questionnaires were being administered, with the aim of standardising procedures and improving compliance. Dedicated local trials staff were funded for CHART but not for the other trials. In all three trials, patients completed a Rotterdam Symptom Checklist (RSCL) and a Hospital Anxiety and Depression Scale (HADS) at specified times. 17 of 22 LU12 centres, 9 of 11 LU13 and all 10 CHART centres returned survey forms. In LU12 and LU13, the category of staff responsible for questionnaires varied widely; in CHART, only research staff were involved. This led to more consistency in CHART centres in the administration and collection of questionnaires, and more frequent checking of forms. However, even the CHART administration, although better than in the other two trials, could not be regarded as standardised. All centres were equally affected by logistical problems. These embraced organisational deficits (e.g. unavailability of staff, lack of questionnaires) and patient-related factors (e.g. patient deemed to be too ill, had difficulty reading or left before completing the form). Patient refusals were an uncommon reason for non-compliance and patients were considered to be generally in favour of QL assessment. As a result of these findings, a number of measures have been put in place to increase standardisation of procedures and improve compliance. These include publishing guidelines for protocol writing, providing centres with guidelines for QL administration and information leaflets for patients, together with introducing staff training.
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Crook A, Duffy A, Girling DJ, Souhami RL, Parmar MK. Survey on the treatment of non-small cell lung cancer (NSCLC) in England and Wales. Eur Respir J 1997; 10:1552-8. [PMID: 9230246 DOI: 10.1183/09031936.97.10071552] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
As an adjunct to a meta-analysis of chemotherapy for non-small cell lung cancer (NSCLC), a survey was conducted in England and Wales of clinicians' views on the role of chemotherapy in NSCLC and the benefits it would have to offer to lead them to change their practice. Radiotherapists, medical oncologists, surgeons and physicians specializing in thoracic medicine, and physicians of palliative medicine were asked their views on the treatment of three case histories of 65 yr old men: Case 1, resected tumour involving a hilar lymph node (tumour (T)2, node (N)1, metastasis (M)0); Case 2, tumour that had spread to mediastinal lymph nodes bilaterally (T2, N3, M0); and Case 3, metastatic cancer (M1) accompanied by minor haemoptysis. Six hundred and ninety eight (85%) of the 821 clinicians responded. For Case 1, 74% would not recommend any adjuvant treatment, 24% would recommend radiotherapy, and <1% chemotherapy, and there was little expectation that adjuvant treatment would improve survival. For Case 2, 68% would recommend radiotherapy, 11% chemotherapy, and 1% surgery, 7% recommending a combination. Adjuvant treatment, regardless of modality, was expected to improve survival. For Case 3, only 11% would recommend chemotherapy, but 26% if the patient was aged < or = 50 yrs. There was little expectation of survival beyond 1 yr, or of improving survival with chemotherapy. For all three cases, most of those not recommending chemotherapy would require it to achieve substantially improved survival for them to use it routinely. Surgery alone is currently considered sufficient for resectable non-small cell lung cancer. Chemotherapy is rarely recommended for disease of any stage.
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Abstract
Many clinical trials organizations use regular interim analyses to monitor the accruing results in large clinical trials. In disease areas such as cancer, where survival is usually a major outcome variable, ethical considerations may lead to a stipulated requirement for data monitoring of mortality. This monitoring has frequently taken the form of limiting interim analyses to be few in number, and specifying an extreme p-value of, for example, p < 0.001 or p < 0.01 as grounds for early termination of the trial. Group-sequential methods are also used. However, none of these approaches formally assesses the impact that the results of a clinical trial may have upon clinical practice. Thus a trial might be terminated early because of apparent treatment benefits, but might fail to influence sceptical clinicians to modify their future treatment policy. We discuss the application of Bayesian methods, including the use of uninformative, sceptical and enthusiastic priors, and demonstrate that the necessary calculations are both straightforward to perform and easy to interpret statistically and clinically. Methods are illustrated with interim analyses of a clinical trial in oesophageal cancer.
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Fayers PM, Ashby D, Parmar MK. Tutorial in biostatistics Bayesian data monitoring in clinical trials. Stat Med 1997. [PMID: 9232762 DOI: 10.1002/(sici)1097-0258(19970630)16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Many clinical trials organizations use regular interim analyses to monitor the accruing results in large clinical trials. In disease areas such as cancer, where survival is usually a major outcome variable, ethical considerations may lead to a stipulated requirement for data monitoring of mortality. This monitoring has frequently taken the form of limiting interim analyses to be few in number, and specifying an extreme p-value of, for example, p < 0.001 or p < 0.01 as grounds for early termination of the trial. Group-sequential methods are also used. However, none of these approaches formally assesses the impact that the results of a clinical trial may have upon clinical practice. Thus a trial might be terminated early because of apparent treatment benefits, but might fail to influence sceptical clinicians to modify their future treatment policy. We discuss the application of Bayesian methods, including the use of uninformative, sceptical and enthusiastic priors, and demonstrate that the necessary calculations are both straightforward to perform and easy to interpret statistically and clinically. Methods are illustrated with interim analyses of a clinical trial in oesophageal cancer.
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Hall R, Hedlund PO, Ackermann R, Bruchovsky N, Dalesio O, Debruyne F, Murphy GP, Parmar MK, Pavone-Macaluso M, Ruutu M, Smith P. Evaluation and follow-up of patients with N1-3 M0 or NXM1 prostate cancer in phase III trials. Urology 1997; 49:39-45. [PMID: 9111613 DOI: 10.1016/s0090-4295(99)80322-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES The aim of this discussion is to review the design and conduct of phase III trials in metastatic prostate cancer, to seek ways of improving their study design, accuracy, relevance to clinical practice, acceptability to patients, and ease of participation by clinicians. We also aim to try to set uniform definitions for the evaluation of the different endpoints used in clinical trials on metastasized prostate cancer. METHODS The work was started by correspondence between the participants in the group for the year before the consensus meeting. Two comprehensive questionnaires were circulated and the answers were distributed to all the members of the group. The statements were finalized during the consensus meeting. RESULTS There were some differing opinions concerning the methods of evaluation of endpoints for follow-up, such as time to tumor progression and time to treatment failure. After the consensus conference, there were no major disagreements within the group. CONCLUSIONS The aim of phase III trials is to influence clinical management. To obtain a credible result they require a sound statistical basis with appropriate power and encompassing patients from small urologic practices as well as large or academic institutions. However, deviation from routine practice may affect the accrual rate, and the trial procedure should therefore be as similar as possible to routine management. Trials inevitably involve extra work and cost. Both should be kept to a minimum to encourage participation and hasten a timely conclusion. It is mandatory to create uniform ways of designing and evaluating clinical trials in prostate cancer.
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Machin D, Stenning SP, Parmar MK, Fayers PM, Girling DJ, Stephens RJ, Stewart LA, Whaley JB. Thirty years of Medical Research Council randomized trials in solid tumours. Clin Oncol (R Coll Radiol) 1997; 9:100-14. [PMID: 9135895 DOI: 10.1016/s0936-6555(05)80448-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This paper reviews the survival outcome from the randomized Phase III trials in solid tumours published on behalf of, or in collaboration with, the Cancer Therapy Committee (CTC) of the British Medical Research Council over a 30-year period to 31 December 1995. We review briefly the innovations in statistical methodology that have occurred over the period. We also note the ways in which standards of reporting the trials have improved, with more recent publications including, for example, estimates of the size of effect and confidence intervals. In all, 32 trials, involving over 5000 deaths in more than 8000 patients, have been published. Tumour types have included bladder, bone, brain, cervix, colon and rectum, head and neck, kidney, lung, ovary, prostate and skin. This paper presents a bibliography of these trials and gives details of the treatment comparisons made, the numbers of patients randomized and included in the analysis for each treatment arm, the observed numbers of deaths, and an estimate of the hazard ratio with associated 95% confidence intervals. The bibliography also indicates the main endpoint of each trial, whether recurrence-free survival or survival, and whether the trial was aimed at finding a difference or showing equivalence. The MRC trials have made an impact on both clinical practice and research activities. For example, the lung cancer programme has helped to establish the role of chemotherapy in small cell lung cancer and has developed better palliative treatment for non-small cell lung cancer. Trials of the radiosensitizer misonidazole have demonstrated that it has no role in the treatment of a number of cancers, trials of hyperbaric oxygen have defined the biological activity of this approach, and the appropriate dose of radiotherapy in patients with brain tumours has been found. The individual trials recruited between 44 and 824 patients (median 213). A better measure of the information in a trial is the number of deaths reported, which varied from 28 to 661 (median 145). A large proportion of the comparisons (8/29 or 28%) anticipating a survival difference, demonstrated such a difference at the 5% level of significance. Despite this, it is concluded that some of the trials should have been larger. In such cases, hindsight suggests either that an overoptimistic view of the anticipated survival benefit was taken at the design stage, or, for equivalence trials, the planned confidence interval was too wide for definitive statements to be made. As a consequence, the current CTC profolio of ongoing randomized trials open to patient accrual at 1 January 1996 have a projected median size of 600 and range from 120 to 2000 patients.
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Pawinski A, Sylvester R, Kurth KH, Bouffioux C, van der Meijden A, Parmar MK, Bijnens L. A combined analysis of European Organization for Research and Treatment of Cancer, and Medical Research Council randomized clinical trials for the prophylactic treatment of stage TaT1 bladder cancer. European Organization for Research and Treatment of Cancer Genitourinary Tract Cancer Cooperative Group and the Medical Research Council Working Party on Superficial Bladder Cancer. J Urol 1996; 156:1934-40, discussion 1940-1. [PMID: 8911360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE The use of prophylactic agents after primary resection can decrease the incidence of tumor recurrence in patients with stage TaT1 bladder cancer. However, the long-term impact on progression to muscle invasive disease as well as on duration of survival is unknown. A combined analysis of individual patient data from previously performed European Organization for Research and Treatment of Cancer (EORTC) and Medical Research Council (MRC) randomized clinical trials was done in an attempt to answer these crucial questions. We compared immediate versus no adjuvant prophylactic treatment after transurethral resection with respect to disease-free interval, time to progression to muscle invasive disease, time to appearance of distant metastases, duration of survival and progression-free survival. MATERIALS AND METHODS All EORTC and MRC prophylactic, randomized phase III trials with primary or recurrent, stage TaT1 transitional cell bladder cancer that compared transurethral resection alone or with adjuvant prophylactic treatment were included in the study. Four EORTC and 2 MRC trials using intravesical chemotherapy or oral agents and including a total of 2,535 patients were studied. RESULTS A statistically significant effect of adjuvant treatment over no adjuvant treatment was found in terms of the duration of the disease-free interval (p < 0.01). No clear advantage of adjuvant treatment was shown with respect to progression to invasive disease, time to appearance of distant metastases or duration of survival and progression-free survival. Median survival followup was 7.8 years. CONCLUSIONS Despite prologation of the disease-free-interval adjuvant treatment has no apparent long-term impact on the evolution of stage TaTi bladder cancer.
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Parmar MK, Ungerleider RS, Simon R. Assessing whether to perform a confirmatory randomized clinical trial. J Natl Cancer Inst 1996; 88:1645-51. [PMID: 8931608 DOI: 10.1093/jnci/88.22.1645] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND A confirmatory randomized clinical trial is a trial that is aimed at assessing whether a treatment effect observed in a previous randomized trial (or trials) is real and important. There is often considerable disagreement about the need for such confirmatory trials. PURPOSE Our aim is to provide a general statistical framework for evaluating whether a confirmatory trial is warranted in a particular situation. METHODS AND RESULTS The results of two clinical trials are considered: 1) a Cancer and Leukemia Group B trial comparing induction chemotherapy plus radiotherapy with radiotherapy alone in the treatment of patients with locally advanced non-small-cell lung cancer and 2) a North Central Cancer Treatment Group trial comparing surgery plus adjuvant chemotherapy with surgery alone in the treatment of patients with advanced colon cancer. In our analysis, we argue that differences in the interpretation of results from a randomized trial are based on differences in prior beliefs about the efficacy of the treatment(s) under study. We believe that a major factor in the decision to perform a confirmatory trial is prior skepticism about the clinical worth of the treatment in question. Both the level of prior skepticism and the minimum treatment effect deemed clinically worthwhile require subjective judgment. We develop a Bayesian framework to allow differences in interpretation to be examined systematically and the need for a confirmatory trial to be assessed. Our model allows the addition of prior belief (specified in the form of a prior distribution of treatment effect) to the results of a trial to yield a posterior distribution. The interpretation of trial results is based on the posterior distribution and will vary as the prior distribution (i.e., the prior belief) varies. To aid in the interpretation of trial results, we also advocate the specification of a minimum clinically worthwhile treatment effect at the start of a trial. CONCLUSIONS AND IMPLICATIONS Our approach acknowledges that a number of different prior beliefs are possible, giving rise to a range of interpretations of results from a clinical trial. This approach provides a formal and systematic basis for considering both the range of likely opinions and the subsequent decision to be made with regard to the need for a confirmatory trial. We recommend that this approach be considered in the discussion of future confirmatory randomized clinical trials.
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Parmar MK, Stewart LA, Altman DG. Meta-analyses of randomised trials: when the whole is more than just the sum of the parts. Br J Cancer 1996; 74:496-501. [PMID: 8761361 PMCID: PMC2074669 DOI: 10.1038/bjc.1996.392] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Saunders MI, Dische S, Barrett A, Parmar MK, Harvey A, Gibson D. Randomised multicentre trials of CHART vs conventional radiotherapy in head and neck and non-small-cell lung cancer: an interim report. CHART Steering Committee. Br J Cancer 1996; 73:1455-62. [PMID: 8664112 PMCID: PMC2074536 DOI: 10.1038/bjc.1996.276] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
While radiotherapy is proceeding, tumour cells may proliferate. The use of small individual doses reduces late morbidity. Continuous hyperfractionated accelerated radiation therapy (CHART), which reduces overall treatment from 6-7 weeks to 12 days and gives 36 small fractions, has now been tested in multicentre randomised controlled clinical trials. The trial in non-small-cell lung cancer included 563 patients and showed improvement in survival; 30% of the CHART patients were alive at 2 years compared with 20% in the control group (P = 0.006). In the 918 head and neck cases, there was only a small, non-significant improvement in the disease-free interval. In this interim analysis there was a trend for those with more advanced disease (T3 and T4) to show advantage; this will be subject to further analysis when the data are more mature. The early mucosal reactions appeared sooner and were more troublesome with CHART, however they quickly settled; so far no difference in long-term morbidity has emerged. These results support the hypothesis that tumour cell repopulation can occur during a conventional course of radiotherapy and be a cause of treatment failure.
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Tolley DA, Parmar MK, Grigor KM, Lallemand G, Benyon LL, Fellows J, Freedman LS, Grigor KM, Hall RR, Hargreave TB, Munson K, Newling DW, Richards B, Robinson MR, Rose MB, Smith PH, Williams JL, Whelan P. The effect of intravesical mitomycin C on recurrence of newly diagnosed superficial bladder cancer: a further report with 7 years of follow up. J Urol 1996; 155:1233-8. [PMID: 8632538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE We determined the role, if any, of 1 and 5 instillations of intravesical mitomycin C in the treatment of newly diagnosed superficial bladder cancer. MATERIALS AND METHODS A multicenter randomized clinical trial was done involving 502 patients with newly diagnosed superficial bladder cancer. After complete transurethral resection patients with newly diagnosed superficial bladder cancer. After complete resection patients were randomized into 1 of 3 treatment arms: no further treatment, 1 instillation of mitomycin C at resection and 1 instillation at resection and at 3-month intervals for 1 year (total 5 instillations). The dose of mitomycin C used was 40 mg./40 ml. water. End points were interval to first superficial recurrence, recurrence rate (defined as the number of positive cystoscopies per year) and progression-free interval rate (progression defined as the development of muscle invasive or metastatic disease, or death from bladder cancer). RESULTS After median followup of 7 years 1 and 5 instillations of mitomycin C resulted in decreased recurrence rates and increased recurrence-free interval. The benefit of mitomycin C was observed in patients at low, medium and high risk for subsequent recurrence. There was suggestive but not conclusive evidence that 5 instillations of mitomycin C offered a slight advantage over 1 instillation. CONCLUSIONS Our analysis confirms the positive benefit of mitomycin C to decrease the number of subsequent recurrences and increase the recurrence-free interval.
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Stephens RJ, Parmar MK, Souhami RL, Spiro S. Chemotherapy in non-small cell lung cancer. Large trial will reduce uncertainty. Steering Committee of the Big Lung Trial. BMJ (CLINICAL RESEARCH ED.) 1996; 312:248-9. [PMID: 8563601 PMCID: PMC2349996 DOI: 10.1136/bmj.312.7025.248c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Stewart LA, Parmar MK. Bias in the analysis and reporting of randomized controlled trials. Int J Technol Assess Health Care 1996; 12:264-75. [PMID: 8707499 DOI: 10.1017/s0266462300009612] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The most reliable information on any type of medical intervention is provided by the results of randomized clinical trials (RCTs). In response to increasing pressure to make effective use of limited resources, increasing numbers of health professionals rely on the medical literature, in particular reports of RCTs. However, RCTs may be influenced by a number of factors that introduce bias during the conduct, analysis, and reporting of the trial. Trials may be described as random, when in fact only quasi-random means of treatment allocation have been used; patients may be selectively removed from the analysis; and the report may restrict presentation to or give undue emphasis to only the analyses that yield positive results. The implications of such bias are discussed with particular reference to the effect that they may have on reviews and meta-analyses.
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Altman DG, Whitehead J, Parmar MK, Stenning SP, Fayers PM, Machin D. Randomised consent designs in cancer clinical trials. Eur J Cancer 1995; 31A:1934-44. [PMID: 8562145 DOI: 10.1016/0959-8049(95)00470-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In 1977, Zelen proposed a new design for clinical trials with the aim of increasing recruitment by avoiding some of the problems associated with obtaining informed consent. These 'randomised consent' designs have proved controversial, and have not often been used. This paper explains the statistical aspects of single and double randomised consent designs and reviews some of the ethical issues. All identified published cancer treatment trials using a randomised consent design are considered in some detail. Reasons for and against the use of these designs are summarised.
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Tierney JF, Mosseri V, Stewart LA, Souhami RL, Parmar MK. Adjuvant chemotherapy for soft-tissue sarcoma: review and meta-analysis of the published results of randomised clinical trials. Br J Cancer 1995; 72:469-75. [PMID: 7640234 PMCID: PMC2034002 DOI: 10.1038/bjc.1995.357] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Fifteen published randomised trials comparing adjuvant chemotherapy with no chemotherapy in soft-tissue sarcoma (STS) were identified (1546 patients). A qualitative review and a meta-analysis of this published literature were performed. With the qualitative review it was not possible to synthesise the apparently conflicting results of individual trials. The meta-analysis of the published data suggests an improvement in survival at 2 years (OR = 0.73, 95% CI = 0.53-0.99, P = 0.044) and at 5 years (OR = 0.59, 95% CI = 0.45-0.78, P = 0.0002) in favour of chemotherapy. However, the assumptions and approximations required to conduct this quantitative summary demand that the results are interpreted with caution. The only reliable means of assessing the current evidence on whether adjuvant chemotherapy has a role in the treatment of patients with STS, is to collect, check and reanalyse individual patients data (IPD) from each trial centrally, and formally combine the results in a stratified time-to-event analysis. Such an IPD analysis is currently being undertaken by an international collaborative group.
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Machin D, Parmar MK. Hyperthermia in cancer treatment. Lancet 1995; 345:1635-6; author reply 1636-7. [PMID: 7783551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Reading J, Hall RR, Parmar MK. The application of a prognostic factor analysis for Ta.T1 bladder cancer in routine urological practice. BRITISH JOURNAL OF UROLOGY 1995; 75:604-7. [PMID: 7613798 DOI: 10.1111/j.1464-410x.1995.tb07417.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To assess the reproducibility of the prognostic factor findings of Parmar et al. [1], in a routine urological practice. PATIENTS AND METHODS The superficial tumour recurrence-free rate has been analysed for 232 newly diagnosed consecutive patients with Ta.T1 transitional cell carcinoma of the bladder. All patients were without carcinoma in situ or muscle invasion at the time of diagnosis. RESULTS Applying the prognostic factors recommended (number of tumours at diagnosis; tumour recurrence at first 3-month cystoscopy) patients with Ta.T1 bladder cancer may be divided into three distinct groups with significantly different chances of superficial bladder tumour recurrence. CONCLUSION Two simple clinical criteria provide a reliable guide to the likelihood of tumour recurrence in patients with Ta.T1 bladder cancer. The modification of follow-up cystoscopy schedules on this basis requires prospective study.
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Gibson D, Harvey AJ, Everett V, Parmar MK. Is double data entry necessary? The CHART trials. CHART Steering Committee. Continuous, Hyperfractionated, Accelerated Radiotherapy. CONTROLLED CLINICAL TRIALS 1994; 15:482-8. [PMID: 7851109 DOI: 10.1016/0197-2456(94)90005-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
There is some controversy over the need for double data entry in clinical trials. In particular, does the number and types of errors identified with this approach justify the extra effort involved? We report the results of a study carried out to address this question. Our main outcome measure was the frequency and types of errors involved in the entry of data for the CHART (continuous, hyperfractionated, accelerated radiotherapy) trials. Data were reentered for a sample of 44 patients by a data manager other than the one making the initial entry. The second entry was then compared with the first entry. The error rate for the two entries combined was 14 per 10,000 data items (fields) (95% confidence interval 10, 19). The error rate for the initial entry alone was 15 per 10,000 fields (95% confidence interval 9.5, 22), and the vital/important error rate (defined as any error on a principal outcome measure or a major error on any other endpoint or variable) was 2.5 per 10,000 fields (95% confidence interval 0.68, 6.4). On this evidence double data entry is not performed for the CHART trials.
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Grossman J, Parmar MK, Spiegelhalter DJ, Freedman LS. A unified method for monitoring and analysing controlled trials. Stat Med 1994; 13:1815-26. [PMID: 7997715 DOI: 10.1002/sim.4780131804] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Group sequential methods are becoming increasingly popular for monitoring and analysing large controlled trials, especially clinical trials. They not only allow trialists to monitor the data as it accumulates, but also reduce the expected sample size. Such methods are traditionally based on preserving the overall type I error by increasing the conservatism of the hypothesis tests performed at any single analysis. Using methods which are based on hypothesis testing in this way makes point estimation and the calculation of confidence intervals difficult and controversial. We describe a class of group sequential procedures based on a single parameter which reflects initial scepticism towards unexpectedly large effects. These procedures have good expected and maximum sample sizes, and lead to natural point and interval estimates of the treatment difference. Hypothesis tests, point estimates and interval estimates calculated using this procedure are consistent with each other, and tests and estimates made at the end of the trial are consistent with interim tests and estimates. This class of sequential tests can be considered in both a traditional group sequential manner or as a Bayesian solution to the problem.
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Popert RJ, Goodall J, Coptcoat MJ, Thompson PM, Parmar MK, Masters JR. Superficial bladder cancer: the response of a marker tumour to a single intravesical instillation of epirubicin. BRITISH JOURNAL OF UROLOGY 1994; 74:195-9. [PMID: 7921938 DOI: 10.1111/j.1464-410x.1994.tb16585.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To determine the response of a marker tumour to a single instillation of intravesical epirubicin. PATIENTS AND METHODS Eighty-one patients (54 men, 27 women) with a mean age of 69.3 years (range 36-92) with superficial bladder cancer were randomized to receive a single instillation of intravesical epirubicin. At the initial cystoscopy all but one papillary marker tumour was resected. Subsequently the patients were randomized to receive either intravesical epirubicin at a concentration of 1 mg/ml (n = 40) or 2 mg/ml (n = 41) in 50 ml of saline for 1 h. The response of the marker tumour was determined at 3 months (first check cystoscopy). The toxicity associated with both treatments was also recorded. RESULTS A complete response (no visible or microscopic bladder carcinoma) was observed in 46% (95% confidence interval (CI) 35-57%) of patients. No patient experienced systemic side-effects. Chemical cystitis and bladder irritability were the most frequent local side-effects, occurring in 15% (95% CI 8-24%) of the patients. CONCLUSIONS A single instillation of intravesical epirubicin has a demonstrable effect in superficial bladder cancer. The results compare favourably with more onerous regimes. Side-effects were minimal at 1 mg/ml and acceptable at 2 mg/ml.
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