Sarah Burdett

Meta-Analysis of Concomitant Versus Sequential Radiochemotherapy in Locally Advanced Non–Small-Cell Lung Cancer

PURPOSE The previous individual patient data meta-analyses of chemotherapy in locally advanced non-small-cell lung cancer (NSCLC) showed that adding sequential or concomitant chemotherapy to radiotherapy improved survival. The NSCLC Collaborative Group performed a meta-analysis of randomized trials directly comparing concomitant versus sequential radiochemotherapy. METHODS Systematic searches for trials were undertaken, followed by central collection, checking, and reanalysis of updated individual patient data. Results from trials were combined using the stratified log-rank test to calculate pooled hazard ratios (HRs). The primary outcome was overall survival; secondary outcomes were progression-free survival, cumulative incidences of locoregional and distant progression, and acute toxicity. RESULTS Of seven eligible trials, data from six trials were received (1,205 patients, 92% of all randomly assigned patients). Median follow-up was 6 years. There was a significant benefit of concomitant radiochemotherapy on overall survival (HR, 0.84; 95% CI, 0.74 to 0.95; P = .004), with an absolute benefit of 5.7% (from 18.1% to 23.8%) at 3 years and 4.5% at 5 years. For progression-free survival, the HR was 0.90 (95% CI, 0.79 to 1.01; P = .07). Concomitant treatment decreased locoregional progression (HR, 0.77; 95% CI, 0.62 to 0.95; P = .01); its effect was not different from that of sequential treatment on distant progression (HR, 1.04; 95% CI, 0.86 to 1.25; P = .69). Concomitant radiochemotherapy increased acute esophageal toxicity (grade 3-4) from 4% to 18% with a relative risk of 4.9 (95% CI, 3.1 to 7.8; P < .001). There was no significant difference regarding acute pulmonary toxicity. CONCLUSION Concomitant radiochemotherapy, as compared with sequential radiochemotherapy, improved survival of patients with locally advanced NSCLC, primarily because of a better locoregional control, but at the cost of manageable increased acute esophageal toxicity.

Vascular Factors and Risk of Dementia: Design of the Three-City Study and Baseline Characteristics of the Study Population

Objective: To describe the baseline characteristics of the participants in the Three-City (3C) Study, a study aiming to evaluate the risk of dementia and cognitive impairment attributable to vascular factors. Methods: Between 1999 and 2001, 9,693 persons aged 65 years and over, noninstitutionalized, were recruited from the electoral rolls of three French cities, i.e. Bordeaux, Dijon and Montpellier. Health-related data were collected during face-to-face interviews using standardized questionnaires. The baseline examination included cognitive testing and diagnosis of dementia, and assessment of vascular risk factors, including blood pressure measurements, ultrasound examination of the carotid arteries, and measurement of biological parameters (glycemia, total, high-density lipoprotein and low-density lipoprotein cholesterol, triglycerides, creatinemia); 3,442 magnetic resonance imaging (MRI) examinations were performed in subjects aged 65–79. Measurements of ultrasound, blood, and MRI parameters were centralized. Two follow-up examinations (at 2 and 4 years) were planned. Results: After exclusion of the participants who had subsequently refused the medical interview, the 3C Study sample consisted of 3,649 men (39.3%) and 5,645 women, mean age 74.4 years, with a relatively high level of education and income. Forty-two percent of the participants reported to be followed up for hypertension, about one third for hypercholesterolemia, and 8% for diabetes; 65% had elevated blood pressure measures (systolic blood pressure ≧140 or diastolic blood pressure ≧90). The proportion of Mini-Mental State Examination scores below 24 was 7% and dementia was diagnosed in 2.2% of the participants. Conclusion: Distribution of baseline characteristics of the 3C Study participants suggests that this study will provide a unique opportunity to estimate the risk of dementia attributable to vascular factors.

A systematic review and meta-analysis of the literature: chemotherapy and surgery versus surgery alone in non-small cell lung cancer

Background: The effectiveness of preoperative chemotherapy in the treatment of non-small cell lung cancer has remained unclear despite the conduct of several randomized controlled trials (RCTs). Methods: A systematic review and meta-analysis was carried out to assess the effectiveness of preoperative chemotherapy in non-small cell lung cancer. This involved identifying eligible RCTs and extracting aggregate data from the abstracts or reports of these RCTs. Hazard ratios were calculated from these published summary statistics and then combined to give pooled estimates of treatment efficacy. Results: Twelve eligible RCTs were identified, from which data from seven RCTs, including 988 patients (75% of eligible patients), could be combined in a systematic review and meta-analysis. Preoperative chemotherapy improved survival with a hazard ratio of 0.82 (95% confidence interval, 0.69–0.97; p = 0.02). 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. Conclusions: This analysis shows a significant benefit of preoperative chemotherapy and is currently the best estimate of the effectiveness of this therapy, but this is based on a small number of trials and patients. This current analysis was unable to address important questions such as whether particular types of patients may benefit more or less from preoperative chemotherapy or whether the early stopping of a number of included RCTs impacted on the results. To assess this, an individual patient data meta-analysis is required.

Addition of docetaxel or bisphosphonates to standard of care in men with localised or metastatic, hormone-sensitive prostate cancer: a systematic review and meta-analyses of aggregate data

Summary Background Results from large randomised controlled trials combining docetaxel or bisphosphonates with standard of care in hormone-sensitive prostate cancer have emerged. In order to investigate the effects of these therapies and to respond to emerging evidence, we aimed to systematically review all relevant trials using a framework for adaptive meta-analysis. Methods For this systematic review and meta-analysis, we searched MEDLINE, Embase, LILACS, and the Cochrane Central Register of Controlled Trials, trial registers, conference proceedings, review articles, and reference lists of trial publications for all relevant randomised controlled trials (published, unpublished, and ongoing) comparing either standard of care with or without docetaxel or standard of care with or without bisphosphonates for men with high-risk localised or metastatic hormone-sensitive prostate cancer. For each trial, we extracted hazard ratios (HRs) of the effects of docetaxel or bisphosphonates on survival (time from randomisation until death from any cause) and failure-free survival (time from randomisation to biochemical or clinical failure or death from any cause) from published trial reports or presentations or obtained them directly from trial investigators. HRs were combined using the fixed-effect model (Mantel-Haenzsel). Findings We identified five eligible randomised controlled trials of docetaxel in men with metastatic (M1) disease. Results from three (CHAARTED, GETUG-15, STAMPEDE) of these trials (2992 [93%] of 3206 men randomised) showed that the addition of docetaxel to standard of care improved survival. The HR of 0·77 (95% CI 0·68–0·87; p<0·0001) translates to an absolute improvement in 4-year survival of 9% (95% CI 5–14). Docetaxel in addition to standard of care also improved failure-free survival, with the HR of 0·64 (0·58–0·70; p<0·0001) translating into a reduction in absolute 4-year failure rates of 16% (95% CI 12–19). We identified 11 trials of docetaxel for men with locally advanced disease (M0). Survival results from three (GETUG-12, RTOG 0521, STAMPEDE) of these trials (2121 [53%] of 3978 men) showed no evidence of a benefit from the addition of docetaxel (HR 0·87 [95% CI 0·69–1·09]; p=0·218), whereas failure-free survival data from four (GETUG-12, RTOG 0521, STAMPEDE, TAX 3501) of these trials (2348 [59%] of 3978 men) showed that docetaxel improved failure-free survival (0·70 [0·61–0·81]; p<0·0001), which translates into a reduced absolute 4-year failure rate of 8% (5–10). We identified seven eligible randomised controlled trials of bisphosphonates for men with M1 disease. Survival results from three of these trials (2740 [88%] of 3109 men) showed that addition of bisphosphonates improved survival (0·88 [0·79–0·98]; p=0·025), which translates to 5% (1–8) absolute improvement, but this result was influenced by the positive result of one trial of sodium clodronate, and we found no evidence of a benefit from the addition of zoledronic acid (0·94 [0·83–1·07]; p=0·323), which translates to an absolute improvement in survival of 2% (−3 to 7). Of 17 trials of bisphosphonates for men with M0 disease, survival results from four trials (4079 [66%] of 6220 men) showed no evidence of benefit from the addition of bisphosphonates (1·03 [0·89–1·18]; p=0·724) or zoledronic acid (0·98 [0·82–1·16]; p=0·782). Failure-free survival definitions were too inconsistent for formal meta-analyses for the bisphosphonate trials. Interpretation The addition of docetaxel to standard of care should be considered standard care for men with M1 hormone-sensitive prostate cancer who are starting treatment for the first time. More evidence on the effects of docetaxel on survival is needed in the M0 disease setting. No evidence exists to suggest that zoledronic acid improves survival in men with M1 or M0 disease, and any potential benefit is probably small. Funding Medical Research Council UK.

Meta-analysis when only the median survival times are known: A comparison with individual patient data results

BACKGROUND The hazard ratio (HR) is the most appropriate measure for time to event outcomes such as survival. In systematic reviews, HRs can be calculated either from the raw trial data obtained as part of an individual patient data (IPD) meta-analysis or from the appropriate trial-level summary statistics. However, the information required for the latter are seldom reported in sufficient detail to allow reviewers to calculate HRs. In contrast, the median survival and survival rates at specific time points are frequently presented. We aimed to evaluate retrospectively the performance of meta-analyses using median survival times and survival rates by comparing them with meta-analyses using IPD to calculate HRs. METHODS IPD from thirteen published meta-analyses (MAs) in cancers with high mortality rates were used. Median survival and survival rates were calculated from the IPD rather than taken from publications so that the same trials, patients, and extended follow-up are used in each analysis. RESULTS AND CONCLUSIONS We show that using median survival times or survival rates at a particular point in time are not reasonable surrogate measures for meta-analyses of survival outcomes and that, wherever possible, HRs should be calculated. Individual trial publications reporting on time to event outcomes, therefore, should provide more detailed statistical information, preferably logHRs and their variances, or their estimators.

Can trial quality be reliably assessed from published reports of cancer trials: evaluation of risk of bias assessments in systematic reviews

Objective To evaluate the reliability of risk of bias assessments based on published trial reports, for determining trial inclusion in meta-analyses. Design Reliability evaluation of risk of bias assessments. Data sources 13 published individual participant data (IPD) meta-analyses in cancer were used to source 95 randomised controlled trials. Review methods Risk of bias was assessed using the Cochrane risk of bias tool (RevMan5.1) and accompanying guidance. Assessments were made for individual risk of bias domains and overall for each trial, using information from either trial reports alone or trial reports with additional information collected for IPD meta-analyses. Percentage agreements were calculated for individual domains and overall (<66%=low, ≥66%=fair, ≥90%=good). The two approaches were considered similarly reliable only when agreement was good. Results Percentage agreement between the two methods for sequence generation and incomplete outcome data was fair (69.5% (95% confidence interval 60.2% to 78.7%) and 80.0% (72.0% to 88.0%), respectively). However, percentage agreement was low for allocation concealment, selective outcome reporting, and overall risk of bias (48.4% (38.4% to 58.5%), 42.1% (32.2% to 52.0%), and 54.7% (44.7% to 64.7%), respectively). Supplementary information reduced the proportion of unclear assessments for all individual domains, consequently increasing the number of trials assessed as low risk of bias (and therefore available for inclusion in meta-analyses) from 23 (23%) based on publications alone to 66 (66%) based on publications with additional information. Conclusions Using cancer trial publications alone to assess risk of bias could be unreliable; thus, reviewers should be cautious about using them as a basis for trial inclusion, particularly for those trials assessed as unclear risk. Supplementary information from trialists should be sought to enable appropriate assessments and potentially reduce or overcome some risks of bias. Furthermore, guidance should ensure clarity on what constitutes risk of bias, particularly for the more subjective domains.

Adding abiraterone to androgen deprivation therapy in men with metastatic hormone-sensitive prostate cancer: a systematic review and meta-analysis

Background There is a need to synthesise the results of numerous randomised controlled trials evaluating the addition of therapies to androgen deprivation therapy (ADT) for men with metastatic hormone-sensitive prostate cancer (mHSPC). This systematic review aims to assess the effects of adding abiraterone acetate plus prednisone/prednisolone (AAP) to ADT. Methods Using our framework for adaptive meta-analysis (FAME), we started the review process before trials had been reported and worked collaboratively with trial investigators to anticipate when eligible trial results would emerge. Thus, we could determine the earliest opportunity for reliable meta-analysis and take account of unavailable trials in interpreting results. We searched multiple sources for trials comparing AAP plus ADT versus ADT in men with mHSPC. We obtained results for the primary outcome of overall survival (OS), secondary outcomes of clinical/radiological progression-free survival (PFS) and grade III–IV and grade V toxicity direct from trial teams. Hazard ratios (HRs) for the effects of AAP plus ADT on OS and PFS, Peto Odds Ratios (Peto ORs) for the effects on acute toxicity and interaction HRs for the effects on OS by patient subgroups were combined across trials using fixed-effect meta-analysis. Findings We identified three eligible trials, one of which was still recruiting (PEACE-1 (NCT01957436)). Results from the two remaining trials (LATITUDE (NCT01715285) and STAMPEDE (NCT00268476)), representing 82% of all men randomised to AAP plus ADT versus ADT (without docetaxel in either arm), showed a highly significant 38% reduction in the risk of death with AAP plus ADT (HR = 0.62, 95% confidence interval [CI] = 0.53–0.71, p = 0.55 × 10−10), that translates into a 14% absolute improvement in 3-year OS. Despite differences in PFS definitions across trials, we also observed a consistent and highly significant 55% reduction in the risk of clinical/radiological PFS (HR = 0.45, 95% CI = 0.40–0.51, p = 0.66 × 10−36) with the addition of AAP, that translates to a 28% absolute improvement at 3 years. There was no evidence of a difference in the OS benefit by Gleason sum score, performance status or nodal status, but the size of the benefit may vary by age. There were more grade III–IV acute cardiac, vascular and hepatic toxicities with AAP plus ADT but no excess of other toxicities or death. Interpretation Adding AAP to ADT is a clinically effective treatment option for men with mHSPC, offering an alternative to docetaxel for men who are starting treatment for the first time. Future research will need to address which of these two agents or whether their combination is most effective, and for whom.

Should Tyrosine Kinase Inhibitors Be Considered for Advanced Non–Small-Cell Lung Cancer Patients With Wild Type EGFR? Two Systematic Reviews and Meta-Analyses of Randomized Trials

Guidance concerning tyrosine kinase inhibitors (TKIs) for patients with wild type epidermal growth factor receptor (EGFR) and advanced non–small-cell lung cancer (NSCLC) after first-line treatment is unclear. We assessed the effect of TKIs as second-line therapy and maintenance therapy after first-line chemotherapy in two systematic reviews and meta-analyses, focusing on patients without EGFR mutations. Systematic searches were completed and data extracted from eligible randomized controlled trials. Three analytical approaches were used to maximize available data. Fourteen trials of second-line treatment (4388 patients) were included. Results showed the effect of TKIs on progression-free survival (PFS) depended on EGFR status (interaction hazard ratio [HR], 2.69; P = .004). Chemotherapy benefited patients with wild type EGFR (HR, 1.31; P < .0001), TKIs benefited patients with mutations (HR, 0.34; P = .0002). Based on 12 trials (85% of randomized patients) the benefits of TKIs on PFS decreased with increasing proportions of patients with wild type EGFR (P = .014). Six trials of maintenance therapy (2697 patients) were included. Results showed that although the effect of TKIs on PFS depended on EGFR status (interaction HR, 3.58; P < .0001), all benefited from TKIs (wild type EGFR: HR, 0.82; P = .01; mutated EGFR: HR, 0.24; P < .0001). There was a suggestion that benefits of TKIs on PFS decreased with increasing proportions of patients with wild type EGFR (P = .11). Chemotherapy should be standard second-line treatment for patients with advanced NSCLC and wild type EGFR. TKIs might be unsuitable for unselected patients. TKIs appear to benefit all patients compared with no active treatment as maintenance treatment, however, direct comparisons with chemotherapy are needed.

A systematic search for reports of site monitoring technique comparisons in clinical trials

Background As part of a broader methodological programme of work around clinical trial monitoring, we wanted to evaluate the existing evidence for the effectiveness of different monitoring techniques. Purpose To identify and evaluate prospective studies of the effectiveness of different monitoring strategies. Methods A systematic search of MEDLINE from 1950 onwards, using free-text terms to identify relevant published studies. We intended to extract data on details of comparative techniques, monitoring findings identified by different techniques, and recommendations or identification of areas in need of further research made by authors. Results A total of 1222 published abstracts were identified and reviewed. Of these, nine articles described methods for quality control (QC) of clinical trial activities, and one article was identified that compared the same monitoring technique at two timepoints. None included a direct comparison of different monitoring techniques and findings. Limitations The search strategy was limited to MEDLINE. However, MEDLINE includes all the journals that tend to report trial methodological research. Conclusions There is a lack of published empirical data that compare monitoring strategies prospectively. Assessment of the usefulness and cost-effectiveness of monitoring techniques in a variety of clinical trial settings and indications is needed.

How individual participant data meta-analyses have influenced trial design, conduct, and analysis

Objectives To demonstrate how individual participant data (IPD) meta-analyses have impacted directly on the design and conduct of trials and highlight other advantages IPD might offer. Study Design and Setting Potential examples of the impact of IPD meta-analyses on trials were identified at an international workshop, attended by individuals with experience in the conduct of IPD meta-analyses and knowledge of trials in their respective clinical areas. Experts in the field who did not attend were asked to provide any further examples. We then examined relevant trial protocols, publications, and Web sites to verify the impacts of the IPD meta-analyses. A subgroup of workshop attendees sought further examples and identified other aspects of trial design and conduct that may inform IPD meta-analyses. Results We identified 52 examples of IPD meta-analyses thought to have had a direct impact on the design or conduct of trials. After screening relevant trial protocols and publications, we identified 28 instances where IPD meta-analyses had clearly impacted on trials. They have influenced the selection of comparators and participants, sample size calculations, analysis and interpretation of subsequent trials, and the conduct and analysis of ongoing trials, sometimes in ways that would not possible with systematic reviews of aggregate data. We identified additional potential ways that IPD meta-analyses could be used to influence trials. Conclusions IPD meta-analysis could be better used to inform the design, conduct, analysis, and interpretation of trials.