Adjuvant chemotherapy, with or without postoperative radiotherapy, in operable non-small-cell lung cancer: two meta-analyses of individual patient data.

BACKGROUND: Many randomised controlled trials have investigated the effect of adjuvant chemotherapy in operable non-small-cell lung cancer. We undertook two comprehensive systematic reviews and meta-analyses to establish the effects of adding adjuvant chemotherapy to surgery, or to surgery plus radiotherapy. METHODS: We included randomised trials, not confounded by additional therapeutic differences between the two groups and that started randomisation on or after Jan 1, 1965, which compared surgery plus adjuvant chemotherapy versus surgery alone, or surgery plus adjuvant radiotherapy and chemotherapy versus surgery plus adjuvant radiotherapy. Updated individual patient data were collected, checked, and included in meta-analyses stratified by trial. The primary endpoint was overall survival, defined as time from randomisation until death by any cause. All analyses were by intention to treat. FINDINGS: The first meta-analysis of surgery plus chemotherapy versus surgery alone was based on 34 trial comparisons and 8447 patients (3323 deaths). We recorded a benefit of adding chemotherapy after surgery (hazard ratio [HR] 0.86, 95% CI 0.81-0.92, p<0.0001), with an absolute increase in survival of 4% (95% CI 3-6) at 5 years (from 60% to 64%). The second meta-analysis of surgery plus radiotherapy and chemotherapy versus surgery plus radiotherapy was based on 13 trial comparisons and 2660 patients (1909 deaths). We recorded a benefit of adding chemotherapy to surgery plus radiotherapy (HR 0.88, 95% CI 0.81-0.97, p=0.009), representing an absolute improvement in survival of 4% (95% CI 1-8) at 5 years (from 29% to 33%). In both meta-analyses we noted little variation in effect according to the type of chemotherapy, other trial characteristics, or patient subgroup. INTERPRETATION: The addition of adjuvant chemotherapy after surgery for patients with operable non-small-cell lung cancer improves survival, irrespective of whether chemotherapy was adjuvant to surgery alone or adjuvant to surgery plus radiotherapy. FUNDING: UK Medical Research Council, Institut Gustave-Roussy, Programme Hospitalier de Recherche Clinique (AOM 05 209), Ligue Nationale Contre le Cancer, and Sanofi-Aventis.

Single photon emission from diamond nanocrystals in an opal photonic crystal.

We present the first optical measurement of a single nitrogen-vacancy (NV) center in a three-dimensional photonic crystal. The photonic crystal, fabricated by self-assembly of polystyrene microspheres, exhibits a photonic stopband that overlaps the NV photoluminescence spectrum. A modified emission spectrum and photon antibunching were measured from the NV centers. Time-resolved fluorescence measurements revealed a 30% increase in the source lifetime. Encapsulation of single NV centers in a three-dimensional photonic crystal is a step towards controlling emission properties of a single photon source.

Chemotherapy and surgery versus surgery alone in non-small cell lung cancer.

BACKGROUND: The role of pre-operative chemotherapy in the treatment of patients with non-small cell lung cancer (NSCLC) was not clear. A systematic review and quantitative meta-analysis were therefore undertaken to evaluate the available evidence from randomised trials. OBJECTIVES: To evaluate the effect of pre-operative chemotherapy on survival in patients with non-small cell lung cancer. If adequate data are available, to investigate whether or not pre-defined patient subgroups benefit more or less from pre-operative chemotherapy. SEARCH STRATEGY: MEDLINE and CANCERLIT searches for randomised controlled trials (RCTs) were supplemented by information from trial registers and by handsearching relevant meeting proceedings and by discussion with relevant trialists and organisations. SELECTION CRITERIA: RCTs were eligible for inclusion provided the patients had been randomised between chemotherapy followed by surgery versus surgery alone and that the method of randomisation precluded prior knowledge of the treatment to be assigned. DATA COLLECTION AND ANALYSIS: A systematic review and meta-analysis based on aggregate data extracted from trial publications was carried out to assess the effectiveness of pre-operative chemotherapy in NSCLC. This involved identifying eligible RCTs and extracting aggregate data from the abstracts or reports of these RCTs. Hazard ratios were calculated from published summary statistics and then combined to give pooled estimates of treatment efficacy. MAIN RESULTS: Twelve eligible RCTs were identified. Data were available from seven RCTs including 988 patients (75% of eligible patients). Pre-operative chemotherapy increased survival with a hazard ratio of 0.82 (95%CI 0.69-0.97) P = 0.022. This is equivalent to an absolute benefit of 6%, increasing overall survival across all stages of disease from 14% to 20% at 5 years. There was no evidence of statistical heterogeneity (P = 0.980, I(2 )= 0). AUTHORS' CONCLUSIONS: This analysis shows a significant increase in survival attributable to pre-operative chemotherapy. This is currently the best estimate of the effectiveness of this therapy, but is based on a small number of trials and patients. This analysis was unable to address important questions such as whether particular types of patients may benefit more or less from pre-operative chemotherapy or whether the early stopping of a number of included RCTs impacted on the results. These issues may be addressed by an ongoing individual patient data (IPD) meta-analysis.

Can the published data tell us about the effectiveness of neoadjuvant chemotherapy for locally advanced cancer of the uterine cervix?

The effect of neoadjuvant chemotherapy on survival of patients with locally advanced cervical cancer was investigated by conducting a systematic review and meta-analysis of the published data. Of the 21 randomised trials that we identified, only 15 were published. Furthermore, 2-year survival data could be extracted from only seven trial reports and 3-year survival from only nine trial reports. Meta-analyses of the published data at 2 and 3 years are neither clearly in favour of neoadjuvant chemotherapy nor control (2 years: odds ratio (OR) = 1.09, 95% confidence interval (CI) = 0.83-1.45, P = 0.37; 3 years: OR = 0.96, 95% confidence interval (CI) = 0.73-1.25, P = 0.45). Being restricted to only some of the data from a relatively small fraction of the randomised trials, these analyses potentially suffer from a number of biases and are therefore inconclusive. The only reliable way to judge the value of neoadjuvant chemotherapy in this disease is to perform a meta-analysis of centrally collected, updated, individual data on all patients from all known randomised trials. Such an analysis is currently being carried out by an international collaborative group.

Preoperative radiotherapy in esophageal carcinoma: a meta-analysis using individual patient data (Oesophageal Cancer Collaborative Group).

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%).

Modification of sleep respiratory patterns by auditory stimulation: indications of a technique for preventing sudden infant death syndrome?

Sudden infant death syndrome (SIDS) has been associated with premorbid respiratory irregularities that may contribute to the subsequent occurrence of SIDS (e.g. by chronic hypoxia). Conventional apnea alarms will detect periods of extended apnea but not other chronic respiratory irregularities that could contribute to SIDS. The effect of a brief, quiet, repetitive auditory stimulus on the sleep respiratory behavior of infant dogs and pigs was assessed. Stimulus presentation was associated with an increase in the sleep respiration rate irrespective of the stimulus presentation rate being faster or slower than the baseline respiratory rate, and irrespective of the pattern of presentation being regular or random. These results suggest that apnea monitoring systems may be improved by an additional function in which less extreme respiratory irregularities initiate the time-limited presentation of a quiet, repetitive, auditory stimulus, aimed at normalizing the respiratory pattern. This function could enhance the preventative role of the alarm systems by reducing the development of pathology that may promote some instances of SIDS.

Comparison of in vivo and in vitro measures of beryllium sensitization.

Chronic beryllium disease (CBD) diagnosis hinges on demonstrating a cell-mediated immune response to beryllium salts in vitro with the beryllium lymphocyte proliferation test (BeLPT). The BeLPT has found widespread application in screening for CBD and beryllium sensitization in populations of exposed workers. We hypothesized that the in vivo beryllium salt patch test may be of value as an adjunct to the BeLPT, rectifying false negative or ambiguous blood test results. We studied subjects with CBD (n = 11), beryllium sensitization without disease (n = 3), and control subjects with dermatitis (n = 20). Evaluation included completion of a demographic questionnaire, blood BeLPT (if CBD or beryllium-sensitized), and beryllium patch testing with 0.1% and 1% beryllium sulfate (BeSO4) in petrolatum and in aqueous vehicles. Biopsies were performed at abnormal patch test sites in five subjects. The 1% aqueous BeSO4 proved superior either to 1% petrolatum or 0.1% solutions, producing positive reactions in all CBD and beryllium-sensitized subjects. We observed no long-term adverse reactions. Biopsies demonstrated spongiotic changes early, followed by noncaseating granulomas within 18 days. We conclude that the beryllium patch test can be used safely to clarify the sensitization state and diagnosis of CBD.

Preoperative radiotherapy for esophageal carcinoma.

BACKGROUND: The existing randomized evidence has failed to conclusively demonstrate the benefit or otherwise of preoperative radiotherapy in treating patients with potentially resectable esophageal carcinoma. OBJECTIVES: This meta-analysis aimed to assess whether there is benefit from adding radiotherapy prior to surgery and whether or not any pre-defined patient subgroups benefit more or less from preoperative radiotherapy SEARCH STRATEGY: Medline and CancerLit searches were supplemented by information from trial registers and by hand searching relevant meeting proceedings and by discussion with relevant trialists, organisations and industry. The search strategy was run again in Medline, Embase and the Cochrane Library on 2nd May 2000, one year after original publication. No new trials were found. SELECTION CRITERIA: Trials were eligible for inclusion in this meta-analysis provided they randomized patients with potentially resectable carcinoma of the esophagus (of any histological type) to receive radiotherapy or no radiotherapy prior to surgery. Trials must have used a randomization method which precluded prior knowledge of treatment assignment and completed accrual by December 1993, to ensure sufficient follow-up by the time of the first analysis (September 1995). DATA COLLECTION AND ANALYSIS: A quantitative meta-analysis using updated data from individual patients from all properly randomized trials (published or unpublished) comprising 1147 patients (971 deaths) from five randomized trials. This approach was used to assess whether preoperative radiotherapy improves overall survival and whether it is differentially effective in patients defined by age, sex and tumour location. MAIN RESULTS: With a median follow-up of 9 years, in a group patients with mostly squamous carcinomas, 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. REVIEWER'S CONCLUSIONS: 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 (90% power, 5% significance level) would be needed to reliably detect such an improvement (from 15 to 20%).

Preoperative radiotherapy for esophageal carcinoma. Oeosphageal Cancer Collaborative Group.

BACKGROUND: The existing randomized evidence has failed to conclusively demonstrate the benefit or otherwise of preoperative radiotherapy in treating patients with potentially resectable esophageal carcinoma. OBJECTIVES: This meta-analysis aimed to assess whether there is benefit from adding radiotherapy prior to surgery and whether or not any pre-defined patient subgroups benefit more or less from preoperative radiotherapy SEARCH STRATEGY: Medline and CancerLit searches were supplemented by information from trial registers and by hand searching relevant meeting proceedings and by discussion with relevant trialists, organisations and industry. SELECTION CRITERIA: Trials were eligible for inclusion in this meta-analysis provided they randomized patients with potentially resectable carcinoma of the esophagus (of any histological type) to receive radiotherapy or no radiotherapy prior to surgery. Trials must have used a randomization method which precluded prior knowledge of treatment assignment and completed accrual by December 1993, to ensure sufficient follow-up by the time of the first analysis (September 1995). DATA COLLECTION AND ANALYSIS: A quantitative meta-analysis using updated data from individual patients from all properly randomized trials (published or unpublished) comprising 1147 patients (971 deaths) from five randomized trials. This approach was used to assess whether preoperative radiotherapy improves overall survival and whether it is differentially effective in patients defined by age, sex and tumour location. MAIN RESULTS: With a median follow-up of 9 years, in a group patients with mostly squamous carcinomas, 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. REVIEWER'S CONCLUSIONS: 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 (90% power, 5% significance level) would be needed to reliably detect such an improvement (from 15 to 20%).

Thirty years of Medical Research Council randomized trials in solid tumours.

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.

The results of a quantitative overview of chemotherapy in advanced ovarian cancer: what can we learn?

The results of a quantitative overview (meta-analysis) of randomised clinical trials, considering the roles of combination chemotherapy and platinum in advanced ovarian cancer are briefly reviewed. This overview collected individual patient data from 45 randomised trials, comprising information from over 8,000 women, but even with this large dataset, no firm conclusions could be reached. However, the results suggest that in terms of survival: i) immediate platinum-based therapy is better than a non-platinum regimen; ii) platinum in combination is better than single-agent platinum when used at the same dose, and iii) carboplatin and cisplatin are equally effective. These results led to the launch of two international randomised clinical trials in ovarian cancer, each of which plans to accrue 2,000 patients.

Systematic reviews of randomized controlled trials: the need for complete data.

If the relative effectiveness of different treatments that might be used in clinical practice is to be evaluated reliably, it is very important that the evaluation is carried out in an appropriate manner. This is especially true where the differences between treatments are expected to be moderate, and so easily obscured by the play of chance or systematic bias. Although such differences are often of considerable clinical importance, they can be difficult to assess and require a large amount of randomized evidence. This evidence can be obtained through prospective randomized controlled trials, meta-analysis of results from past randomized trials, or ideally a combination of the two, with prospective trials contributing to future meta-analyses. Whichever technique is adopted, all possible biases must be minimized through the collection of as much randomized evidence as possible. In meta-analyses, this is best achieved by ensuring that all relevant trials, and all randomized participants in these trials, are included in the analysis. The gold standard for this might be a meta-analysis of individual patient data, in which details for each participant in every trial are collected and analysed centrally. This approach requires considerable time and effort. However, it will add to the analyses that can be performed and will remove many of the problems associated with a reliance on published data alone and some of the problems that can arise from the use of aggregate data. This paper sets out some of the reasons for this and some of the techniques used for individual patient data-based meta-analysis.

Meta-analyses using individual patient data.

Systematic reviews of randomized controlled trials often provide the most reliable information on which to base treatment policy. However, to be reliable, such reviews need to contain a high proportion of all the relevant randomized evidence. This relates both to the need to find all trials and the need to analyse data on all participants. One way to achieve this is through a collaboration in which those responsible for the trials supply data on each randomized patient for an individual patient data meta-analysis. However, such projects require more time and resources than more conventional reviews and are still rare. This paper illustrates how they can help to achieve the aim of using complete data in a systematic review.

Obtaining data from randomised controlled trials: how much do we need for reliable and informative meta-analyses?

Many randomised controlled trials compare treatments that will produce only moderate differences in outcome, but these differences can be clinically important. However, they are difficult to assess reliably and require a large amount of randomised evidence. This can be achieved through large prospective randomised trials which will accrue future patients, the meta-analysis of results from randomised trials involving patients from the past, or--ideally--both. The techniques require that all possible biases are minimised, and in meta-analyses this can best be achieved by ensuring that all of the randomised evidence--both trials and participants in those trials--is included. The meta-analysis of individual patient data has been described as the gold standard for this approach. It will remove many of the problems associated with relying solely on published data and some of the problems arising from a reliance on aggregate data, and will also add to the analyses that can be performed. Such projects, however, require considerable time and effort.

Step-by-step management of female victims of sexual assault.

Various authors have published advice on the management of victims of sexual assault--male and female. Most published accounts provide general advice, ordered according to theoretical considerations rather than to the chronological sequence of tasks to be performed. Our experience has been that a task list sequenced in chronological fashion is very useful in helping the attending doctor to remember what to do and how to do it. The step-by-step list used for women seen at Perth's Sexual Assault Referral Centre (SARC) is presented here.

Essentials of occupational contact dermatitis.

Occupational skin disease constitutes a disproportionately large percentage of all occupational illnesses. It is beneficial for the nurse to have a clear understanding of the relationship between the worker and occupational contact dermatitis. This article describes background information, diagnostic testing, and preventive measures.

Probiotics-supplemented feeding in extremely low-birth-weight infants.

OBJECTIVE: The objective of this trial was to test whether probiotic-supplemented feeding to extremely low-birth-weight (ELBW) infants will improve growth as determined by decreasing the percentage of infants with weight below the 10th percentile at 34 weeks postmenstrual age (PMA). Other important outcome measures, such as improving feeding tolerance determined by tolerating larger volume of feeding per day and reducing antimicrobial treatment days during the first 28 days from the initiation of feeding supplementation were also evaluated. STUDY DESIGN: We conducted a multicenter randomized controlled double-blinded clinical study. The probiotics-supplementation (PS) group received Lactobacillus rhamnosus GG and Bifidobacterium infantis added to the first enteral feeding and continued once daily with feedings thereafter until discharge or until 34 weeks (PMA). The control (C) group received unsupplemented feedings. Infant weight and feeding volumes were recorded daily during the first 28 days of study period. Weights were also recorded at 34 weeks PMA. RESULT: A total of 101 infants were enrolled (PS 50 versus C 51). There was no difference between the two groups in the percentage of infants with weight below the 10th percentile at 34 weeks PMA (PS group 58% versus C group 60%, (P value 0.83)) or in the average volume of feeding during 28 days after study entry (PS group 59 ml kg(-1) versus C group 71 ml kg(-1), (P value 0.11)). Calculated growth velocity was higher in the PS group compared with the C group (14.9 versus 12.6 g per day, (P value 0.05)). Incidences of necrotizing enterocolitis (NEC), as well as mortality were similar between the two groups. CONCLUSION: Although probiotic-supplemented feedings improve growth velocity in ELBW infants, there was no improvement in the percentage of infants with growth delay at 34 weeks PMA. There were no probiotic-related adverse events reported.