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Biomedical subjects

D Machin

Publications and source records attributed to D Machin.

At least 91 records · Page 5Linked to original sources
PubMed1996

Radiotherapy with or without hyperthermia in the treatment of superficial localized breast cancer: results from five randomized controlled trials. International Collaborative Hyperthermia Group.

PURPOSE: Claims for the value of hyperthermia as an adjunct to radiotherapy in the treatment of cancer have mostly been based on small Phase I or II trials. To test the benefit of this form of treatment, randomized Phase III trials were needed. METHODS AND MATERIALS: Five randomized trials addressing this question were started between 1988 and 1991. In these trials, patients were eligible if they had advanced primary or recurrent breast cancer, and local radiotherapy was indicated in preference to surgery. In addition, heating of the lesions and treatment with a prescribed (re)irradiation schedule had to be feasible and informed consent was obtained. The primary endpoint of all trials was local complete response. Slow recruitment led to a decision to collaborate and combine the trial results in one analysis, and report them simultaneously in one publication. Interim analyses were carried out and the trials were closed to recruitment when a previously agreed statistically significant difference in complete response rate was observed in the two larger trials. RESULTS: We report on pretreatment characteristics, the treatments received, the local response observed, duration of response, time to local failure, distant progression and survival, and treatment toxicity of the 306 patients randomized. The overall CR rate for RT alone was 41% and for the combined treatment arm was 59%, giving, after stratification by trial, an odds ratio of 2.3. Not all trials demonstrated an advantage for the combined treatment, although the 95% confidence intervals of the different trials all contain the pooled odds ratio. The greatest effect was observed in patients with recurrent lesions in previously irradiated areas, where further irradiation was limited to low doses. CONCLUSION: The combined result of the five trials has demonstrated the efficacy of hyperthermia as an adjunct to radiotherapy for treatment of recurrent breast cancer. The implication of these encouraging results is that hyperthermia appears to have an important role in the clinical management of this disease, and there should be no doubt that further studies of the use of hyperthermia are warranted.

Breast Neoplasms↗
PubMed1996

Guidelines for reporting results of quality of life assessments in clinical trials.

Clinical trials involving quality of life measurement published in the literature suffer from important weaknesses due to the lack of information on numerous topics. The psychometric properties of the instruments are often lacking as well as data on the number of patients treated and analyzed. The handling of missing data is rarely documented. In order to facilitate the reporting of trials and the evaluation of published results, this article proposes a set of general guidelines for the reporting of clinical trials which include a quality of life assessment. A checklist designed to assist authors is appended.

Clinical Trials as Topic↗
PubMed1996

Long-term survival in small cell lung cancer: the case for a standard definition. Medical Research Council Lung Cancer Working Party.

OBJECTIVES: This paper investigates whether a particular time point can be recommended as the standard definition for long-term survival (LTS) in small cell lung cancer (SCLC). DESIGN: A review of the literature specifically referring to long-term survival in SCLC in the title. Individual and updated survival data from 2196 patients entered into six Medical Research Council (MRC) SCLC randomised trials to investigate changes in the hazard, or risk of death, over time. Examination of subgroups to identify different hazard patterns. SETTING: World-wide literature and patients recruited to SCLC trials conducted by the MRC Lung Cancer Working Party (LCWP). SUBJECTS: Papers accessed through computerised literature and hand searches and 2196 patients from six randomised clinical trials in SCLC conducted by the MRC LCWP. RESULTS: In all, 111 publications were identified by the literature searches. Although the majority defined LTS as 2 years, the definitions ranged from 18 months to greater than 5 years. There thus appears to be no agreed standard definition. The daily hazard was plotted for the large series of patients entered into the MRC LCWP SCLC trials to observe any patterns of change. There was an approximately constant daily hazard of 0.0035 during the first 2 years from randomisation, and following a transitional period, there was a further approximately constant, but smaller, daily hazard of 0.00035 from 3 years onwards. When subgroups of patients were examined this transition to a lower risk was observed in patients with limited disease, but patients with extensive disease remained at a high constant hazard throughout. It is suggested that 3 years should be adopted as the standard definition of LTS in SCLC, and that studies should always report limited and extensive stage patients separately.

Aged↗
PubMed1996

Randomized trial of palliative two-fraction versus more intensive 13-fraction radiotherapy for patients with inoperable non-small cell lung cancer and good performance status. Medical Research Council Lung Cancer Working Party.

In patients with non-metastatic but inoperable non-small cell lung cancer that is locally too extensive for radical radiotherapy (RT), but who have good performance status, it is important to determine whether thoracic RT should be the minimum that is required to palliate thoracic symptoms or whether treatment should be more intensive, with the aim of prolonging survival. A total of 509 such patients from 11 centres in the UK between November 1989 and October 1992 were admitted to a trial comparing palliative versus more intensive RT with respect to survival and quality of life. They were allocated at random to receive thoracic RT with either 17 Gy in two fractions (F2) 1 week apart (255 patients) or 39 Gy in 13 fractions (F13) 5 days per week (254 patients). Survival was better in the F13 group, the median survival periods being 7 months in the F2 group compared with 9 months in the F13 group, and the survival rates 31% and 36% at one year and 9% and 12% at 2 years, respectively (hazard ratio = 0.82; 95% CI0.69-0.99). There was a suggestion of a trend towards greater benefit in fitter patients. Metastases appeared earlier in the F2 group. As recorded by patients using the Rotterdam Symptom Checklist, the commonest symptoms on admission were cough, shortness of breath, tiredness, lack of energy, worrying and chest pain. These were more rapidly palliated by the F2 regimen. Psychological distress was generally lower in the F13 group. Three patients (two F13, one F2) exhibited evidence of myelopathy. As recorded by patients using a diary card, 76% of the F2 compared with 81% of the F13 patients had dysphagia associated with their RT. This was transient, lasting for a median of 6.5 days in the F2 group compared with 14 days in the F13 group. In conclusion, the F2 regimen had a more rapid palliative effect. In the F13 group, although treatment-related dysphagia was worse, survival was longer.

Aged↗
PubMed1996

Radiation myelopathy: estimates of risk in 1048 patients in three randomized trials of palliative radiotherapy for non-small cell lung cancer. The Medical Research Council Lung Cancer Working Party.

Radiation myelopathy (RM) is an uncommon but serious late effect of thoracic radiotherapy (RT), which oncologists try to avoid by careful planning and dose selection. Five patients with RM are described from among 1048 with inoperable non-small cell lung cancer treated with palliative RT in three randomized trials conducted by the Medical Research Council Lung Cancer Working Party. Seven RT regimens were used in these trials: 10 Gy in a single fraction on one day (10/1/1) (114 patients), 17/2/8 (524 patients), 27/6/11 (47 patients), 30/6/11 (36 patients), 30/10/12 (88 patients), 36/12/16 (86 patients) and 39/13/17 (153 patients). Of the five instances of RM, three occurred in the 524 patients treated with 17 Gy in two fractions, and two in the 153 treated with 39 Gy in 13 fractions. The estimated cumulative risks of RM by 2 years were 2.2% for the 17 Gy group, 2.5% for the 39 Gy group, and 0% for the remainder, but the annual risks had wide 95% confidence intervals, indicating that the distribution of episodes among the seven regimens could have been random. Nevertheless, calculation of cord doses in terms of the total doses that would have an equivalent biological effect if given in 2 Gy fractions (LQED2 values) from our data for different values of the ratio of the linear quadratic parameters of the cell survival curve (alpha/beta), suggest that the best estimate of alpha/beta is less than 3 Gy, and possibly close to 2 Gy. This emphasizes the sensitivity of human spinal cord to changes in fraction size. We recommend that, when the computed LQED2 for a schedule of treatment that includes the thoracic spinal cord (assuming alpha/beta = 2 for cord) exceeds 48 Gy, oncologists should consider reducing the dose to the cord.

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PubMed1996

The role of post-operative radiotherapy in non-small-cell lung cancer: a multicentre randomised trial in patients with pathologically staged T1-2, N1-2, M0 disease. Medical Research Council Lung Cancer Working Party.

The role of post-operative radiotherapy for patients with non-small-cell lung cancer (NSCLC) is unclear despite five previous randomised trials. One deficiency with these trials was that they did not include adequate TNM staging, and so the present randomised trial was designed to compare surgery alone (S) with surgery plus post-operative radiotherapy (SR) in patients with pathologically staged T1-2, N1-2. M0 NSCLC. Between July 1986 and October 1993, 308 patients (154 S, 154 SR) were entered from 16 centres in the UK. The median age of the patients was 62 years, 74% were male, > 85% had normal or near normal levels of general condition, activity and breathlessness, 68% had squamous carcinoma, 52% had had a pneumonectomy, 63% had N1 disease and 37% N2 disease. SR patients received 40 Gy in 15 fractions starting 4-6 weeks post-operatively. Overall there was no advantage to either group in terms of survival, although definite local recurrence and bony metastases appeared less frequently and later in the SR group. In a subgroup analysis, in the N1 group no differences between the treatment groups were seen, but in the N2 group SR patients appeared to gain a one month survival advantage, delayed time to local recurrence and time to appearance of the bone metastases. There is, therefore, no clear indication for post-operative radiotherapy in N1 disease, but the question remains unresolved in N2 disease.

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PubMed1996

Assessment of quality of life in clinical trials of the British Medical Research Council.

This article describes aspects of the way the Cancer Therapy Committee of the British Medical Research Council incorporates quality-of-life (QOL) assessments in randomized clinical trials in patients with cancer. The steps taken in incorporating QOL assessments in individual trial protocols are described. The aspects described concern problems associated with choice of instruments, time of assessment, sample size, and analysis. A protocol for patients with small-cell lung cancer that compares oral etoposide with intravenous multidrug chemotherapy is used for illustration.

Clinical Trials, Phase III as Topic↗
PubMed1995

The feasibility of using glycosylated recombinant human granulocyte colony-stimulating factor (G-CSF) to increase the planned dose intensity of doxorubicin, cyclophosphamide and etoposide (ACE) in the treatment of small cell lung cancer. Medical Research Council Lung Cancer Working Party.

This study was conducted to test the feasibility of reducing the interval between cycles of doxorubicin, cyclophosphamide, etoposide (ACE) chemotherapy to 2 weeks, thereby increasing dose intensity, by adding granulocyte colony-stimulating factor (G-CSF) to reduce the duration of neutropenia following a cycle. 20 patients with small cell lung cancer (SCLC) were prescribed six cycles of 2-weekly ACE, with G-CSF on the intermediate days. 3 patients died during the treatment period and a further 5 had ACE terminated, 3 for toxicity and 2 for progressive disease. Of the 71 intervals between cycles, 42 (59%) were of the prescribed 14 days, 9 (13%) of 15-20 days, 15 (21%) of 21 days and five (7%) longer, but during the first four cycles, 36 (77%) of 47 intervals were of 14 days. The main reason for delay was haematological toxicity. All 20 patients experienced WHO grade 3 or 4 neutropenia, but at 2 weeks after a cycle only 3 had grade 4 and 1 grade 3. 17 patients required blood transfusion and 12 platelet transfusion. The only potentially serious adverse reaction to G-CSF was an episode of rash with facial oedema. Adding G-CSF allows ACE chemotherapy to be intensified by reducing the interval between cycles.

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PubMed1995

Randomised consent designs in cancer clinical trials.

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.

Ethics, Medical↗
PubMed1995

Increasing and planned dose intensity of doxorubicin, cyclophosphamide and etoposide (ACE) by adding recombinant human methionyl granulocyte colony-stimulating factor (G-CSF; filgrastim) in the treatment of small cell lung cancer (SCLC). Medical Research Council Lung Cancer Working Party.

The aim of this Phase II study was to test the feasibility of intensifying standard chemotherapy in the treatment of small cell lung cancer (SCLC) by reducing the interval between cycles from 3 to 2 weeks by adding recombinant human methionyl granulocyte colony-stimulating factor (G-CSF; filgrastim) to shorten the duration of neutropenia following each cycle. Thirty-two patients with SCLC were prescribed six cycles of 2-weekly doxorubicin 50 mg/m2 and cyclophosphamide 1 g/m2 on day 1, and etoposide 120 mg/m2 i.v. on days 1, 2 and 3 (ACE), plus filgrastim in a fixed dose of 300 micrograms s.c. on days 4-14 of each cycle. Three patients died during the treatment period and a further nine had chemotherapy terminated before the sixth cycle, all nine because of toxicity. All 32 patients have been followed up for at least 21 months; 14 (44%) were alive at 12 months and the median survival period was 356 days. Of the 127 intervals between cycles of chemotherapy, 74 (58%) were of the prescribed 14 days, 18 (14%) of 15-20 days, 25 (20%) of 21 days, and 10 (8%) were longer. The results were best during the first four cycles, during which 71% of the 83 intervals were of 14 days and a further 10% were less than 21 days. The main reason for delay was haematological toxicity in 37 of the 53 instances. Symptoms of myelosuppression occurred in 23 patients, but at 14 days after a cycle of chemotherapy, all 127 available neutrophil granulocyte counts were normal. Twenty-one patients received blood transfusion and five platelet transfusion. The only adverse effects attributed to filgastrim were episodes of rash, throat swelling, anorexia and shivering, affecting one patient. We conclude that the policy of adding filgrastim allows the dose intensity of ACE chemotherapy to be increased by reducing the intervals between cycles. The findings reinforce those of a parallel study involving lenograstim.

Aged↗
PubMed1995

Sample size: how many patients are necessary?

The need for sample size calculations is briefly reviewed: many of the arguments against small trials are already well known, and we only cursorily repeat them in passing. Problems that arise in the estimation of sample size are then discussed, with particular reference to survival studies. However, most of the issues which we discuss are equally applicable to other types of study. Finally, prognostic factor analysis designs are discussed, since this is another area in which experience shows that far too many studies are of an inadequate size and yield misleading results.

Clinical Trials as Topic↗
PubMed1994

On the development of the Medical Research Council trial of alpha-interferon in metastatic renal carcinoma. Urological Working Party Renal Carcinoma Subgroup.

This paper describes the steps taken by the British Medical Research Council (MRC) in developing the MRC RE01 trial, a randomized clinical trial for patients with metastatic renal cancer; we discuss the reasons for adopting a triangular sequential design and the impact that this has upon the monitoring of the trial. It had been suggested to the MRC that a trial of biological agents for metastatic renal carcinoma should be initiated. The Cancer Therapy Committee (CTC) of the MRC, through its associated site specific working parties, is responsible for designing and co-ordinating randomized trials of alternative treatments in cancer in solid tumours. Since no MRC working party for renal carcinoma existed at that time, development began by the formation of an ad hoc group set up under the auspices of the CTC. They assessed, by means of a postal questionnaire, U.K. interest in the trials of, and modalities utilized for, treatment of renal cancer. The responses focused attention on the important questions to ask and indicated the level of potential collaboration. These responses and related clinical and statistical issues suggested a protocol to compare medroxy-progesterone acetate (MPA) against alpha-interferon (alpha-IFN). In view of the special problems of comparing an expensive and potentially toxic therapy with an inexpensive and non-toxic standard, a sequential design was used rather than a fixed sample size design. Statistical issues raised and solutions provided are described. The method of establishing the trial data monitoring committee and a brief review of mortality from renal carcinoma in England and Wales are also included. The trial opened to patient recruitment on 1 January 1992. The formal statements regarding statistical issues that appear in the formal trial protocol (RE01) are set out in the Appendix.

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PubMed1994

Approaches to the analysis of quality of life data: experiences gained from a medical research council lung cancer working party palliative chemotherapy trial.

Standardization in the choice of quality of life (QOL) instruments and their application in randomised clinical trials have been advocated and generally accepted. However, there is now an urgent need to address the problems relating to the analysis and presentation of the data thus generated. There are intrinsic difficulties associated with QOL data, namely its multidimensional nature, attrition and missing data, and there is no consensus as to how these problems should be dealt with. This paper therefore considers these problems using interim data from a large Medical Research Council randomised trial in patients with small cell lung cancer and a poor prognosis, in which attrition and compliance are major concerns. Three possible approaches to the analysis of these data, which use different subsets of patients, are examined in detail. The strengths and weaknesses of these three methods are discussed, and examples of their use in the literature are given and compared with other reported approaches. The need for a standard definition of compliance is also emphasised, and a method of presentation suggested. The best current advice is that QOL data should be analysed in a number of different ways, and conclusions reached only when consistency is seen.

Antineoplastic Agents↗