A Repurposing Programme Evaluating Transdermal Oestradiol Patches for the Treatment of Prostate Cancer Within the PATCH and STAMPEDE Trials: Current Results and Adapting Trial Design.

AIMS: Androgen deprivation therapy (ADT), usually achieved with luteinising hormone releasing hormone analogues (LHRHa), is central to prostate cancer management. LHRHa reduce both testosterone and oestrogen and are associated with significant long-term toxicity. Previous use of oral oestrogens as ADT was curtailed because of cardiovascular toxicity. Transdermal oestrogen (tE2) patches are a potential alternative ADT, supressing testosterone without the associated oestrogen-depletion toxicities (osteoporosis, hot flushes, metabolic abnormalities) and avoiding cardiovascular toxicity, and we here describe their evaluation in men with prostate cancer. MATERIALS AND METHODS: The PATCH (NCT00303784) adaptive trials programme (incorporating recruitment through the STAMPEDE [NCT00268476] platform) is evaluating the safety and efficacy of tE2 patches as ADT for men with prostate cancer. An initial randomised (LHRHa versus tE2) phase II study (n = 251) with cardiovascular toxicity as the primary outcome measure has expanded into a phase III evaluation. Those with locally advanced (M0) or metastatic (M1) prostate cancer are eligible. To reflect changes in both management and prognosis, the PATCH programme is now evaluating these cohorts separately. RESULTS: Recruitment is complete, with 1362 and 1128 in the M0 and M1 cohorts, respectively. Rates of androgen suppression with tE2 were equivalent to LHRHa, with improved metabolic parameters, quality of life and bone health indices (mean absolute change in lumbar spine bone mineral density of -3.0% for LHRHa and +7.9% for tE2 with an estimated difference between arms of 9.3% (95% confidence interval 5.3-13.4). Importantly, rates of cardiovascular events were not significantly different between the two arms and the time to first cardiovascular event did not differ between treatment groups (hazard ratio 1.11, 95% confidence interval 0.80-1.53; P = 0.54). Oncological outcomes are awaited. FUTURE: Efficacy results for the M0 cohort (primary outcome measure metastases-free survival) are expected in the final quarter of 2023. For M1 patients (primary outcome measure - overall survival), analysis using restricted mean survival time is being explored. Allied translational work on longitudinal samples is underway.

Cediranib in addition to chemotherapy for women with relapsed platinum-sensitive ovarian cancer (ICON6): overall survival results of a phase III randomised trial.

BACKGROUND: Cediranib, an oral anti-angiogenic VEGFR 1-3 inhibitor, was studied at a daily dose of 20 mg in combination with platinum-based chemotherapy and as maintenance in a randomised trial in patients with first relapse of 'platinum-sensitive' ovarian cancer and has been shown to improve progression-free survival (PFS). PATIENTS AND METHODS: ICON6 (NCT00532194) was an international three-arm, double-blind, placebo-controlled randomised trial. Between December 2007 and December 2011, 456 women were randomised, using stratification, to receive either chemotherapy with placebo throughout (arm A, reference); chemotherapy with concurrent cediranib, followed by maintenance placebo (arm B, concurrent); or chemotherapy with concurrent cediranib, followed by maintenance cediranib (arm C, maintenance). Due to an enforced redesign of the trial in September 2011, the primary endpoint became PFS between arms A and C which we have previously published, and the overall survival (OS) was defined as a secondary endpoint, which is reported here. RESULTS: After a median follow-up of 25.6 months, strong evidence of an effect of concurrent plus maintenance cediranib on PFS was observed [hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.44-0.72, P < 0.0001]. In this final update of the survival analysis, 90% of patients have died. There was a 7.4-month difference in median survival and an HR of 0.86 (95% CI: 0.67-1.11, P = 0.24) in favour of arm C. There was strong evidence of a departure from the assumption of non-proportionality using the Grambsch-Therneau test (P = 0.0031), making the HR difficult to interpret. Consequently, the restricted mean survival time (RMST) was used and the estimated difference over 6 years by the RMST was 4.8 months (95% CI: -0.09 to 9.74 months). CONCLUSIONS: Although a statistically significant difference in time to progression was seen, the enforced curtailment in recruitment meant that the secondary analysis of OS was underpowered. The relative reduction in the risk of death of 14% risk of death was not conventionally statistically significant, but this improvement and the increase in the mean survival time in this analysis suggest that cediranib may have worthwhile activity in the treatment of recurrent ovarian cancer and that further research should be undertaken.

Addition of docetaxel to hormonal therapy in low- and high-burden metastatic hormone sensitive prostate cancer: long-term survival results from the STAMPEDE trial.

BACKGROUND: STAMPEDE has previously reported that the use of upfront docetaxel improved overall survival (OS) for metastatic hormone naïve prostate cancer patients starting long-term androgen deprivation therapy. We report on long-term outcomes stratified by metastatic burden for M1 patients. METHODS: We randomly allocated patients in 2 : 1 ratio to standard-of-care (SOC; control group) or SOC + docetaxel. Metastatic disease burden was categorised using retrospectively-collected baseline staging scans where available. Analysis used Cox regression models, adjusted for stratification factors, with emphasis on restricted mean survival time where hazards were non-proportional. RESULTS: Between 05 October 2005 and 31 March 2013, 1086 M1 patients were randomised to receive SOC (n = 724) or SOC + docetaxel (n = 362). Metastatic burden was assessable for 830/1086 (76%) patients; 362 (44%) had low and 468 (56%) high metastatic burden. Median follow-up was 78.2 months. There were 494 deaths on SOC (41% more than the previous report). There was good evidence of benefit of docetaxel over SOC on OS (HR = 0.81, 95% CI 0.69-0.95, P = 0.009) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P = 0.827). Analysis of other outcomes found evidence of benefit for docetaxel over SOC in failure-free survival (HR = 0.66, 95% CI 0.57-0.76, P < 0.001) and progression-free survival (HR = 0.69, 95% CI 0.59-0.81, P < 0.001) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P > 0.5 in each case). There was no evidence that docetaxel resulted in late toxicity compared with SOC: after 1 year, G3-5 toxicity was reported for 28% SOC and 27% docetaxel (in patients still on follow-up at 1 year without prior progression). CONCLUSIONS: The clinically significant benefit in survival for upfront docetaxel persists at longer follow-up, with no evidence that benefit differed by metastatic burden. We advocate that upfront docetaxel is considered for metastatic hormone naïve prostate cancer patients regardless of metastatic burden.

What is the optimal systemic treatment of men with metastatic, hormone-naive prostate cancer? A STOPCAP systematic review and network meta-analysis.

Background: Our prior Systemic Treatment Options for Cancer of the Prostate systematic reviews showed improved survival for men with metastatic hormone-naive prostate cancer when abiraterone acetate plus prednisolone/prednisone (AAP) or docetaxel (Doc), but not zoledronic acid (ZA), were added to androgen-deprivation therapy (ADT). Trial evidence also suggests a benefit of combining celecoxib (Cel) with ZA and ADT. To establish the optimal treatments, a network meta-analysis (NMA) was carried out based on aggregate data (AD) from all available studies. Methods: Overall survival (OS) and failure-free survival data from completed Systemic Treatment Options for Cancer of the Prostate reviews of Doc, ZA and AAP and from recent trials of ZA and Cel contributed to this comprehensive AD-NMA. The primary outcome was OS. Correlations between treatment comparisons within one multi-arm, multi-stage trial were estimated from control-arm event counts. Network consistency and a common heterogeneity variance were assumed. Results: We identified 10 completed trials which had closed to recruitment, and one trial in which recruitment was ongoing, as eligible for inclusion. Results are based on six trials including 6204 men (97% of men randomised in all completed trials). Network estimates of effects on OS were consistent with reported comparisons with ADT alone for AAP [hazard ration (HR) = 0.61, 95% confidence interval (CI) 0.53-0.71], Doc (HR = 0.77, 95% CI 0.68-0.87), ZA + Cel (HR = 0.78, 95% CI 0.62-0.97), ZA + Doc (HR = 0.79, 95% CI 0.66-0.94), Cel (HR = 0.94 95% CI 0.75-1.17) and ZA (HR = 0.90 95% CI 0.79-1.03). The effect of ZA + Cel is consistent with the additive effects of the individual treatments. Results suggest that AAP has the highest probability of being the most effective treatment both for OS (94% probability) and failure-free survival (100% probability). Doc was the second-best treatment of OS (35% probability). Conclusions: Uniquely, we have included all available results and appropriately accounted for inclusion of multi-arm, multi-stage trials in this AD-NMA. Our results support the use of AAP or Doc with ADT in men with metastatic hormone-naive prostate cancer. AAP appears to be the most effective treatment, but it is not clear to what extent and whether this is due to a true increased benefit with AAP or the variable features of the individual trials. To fully account for patient variability across trials, changes in prognosis or treatment effects over time and the potential impact of treatment on progression, a network meta-analysis based on individual participant data is in development.

Adding abiraterone or docetaxel to long-term hormone therapy for prostate cancer: directly randomised data from the STAMPEDE multi-arm, multi-stage platform protocol.

Background: Adding abiraterone acetate with prednisolone (AAP) or docetaxel with prednisolone (DocP) to standard-of-care (SOC) each improved survival in systemic therapy for advanced or metastatic prostate cancer: evaluation of drug efficacy: a multi-arm multi-stage platform randomised controlled protocol recruiting patients with high-risk locally advanced or metastatic PCa starting long-term androgen deprivation therapy (ADT). The protocol provides the only direct, randomised comparative data of SOC + AAP versus SOC + DocP. Method: Recruitment to SOC + DocP and SOC + AAP overlapped November 2011 to March 2013. SOC was long-term ADT or, for most non-metastatic cases, ADT for ≥2 years and RT to the primary tumour. Stratified randomisation allocated pts 2 : 1 : 2 to SOC; SOC + docetaxel 75 mg/m2 3-weekly×6 + prednisolone 10 mg daily; or SOC + abiraterone acetate 1000 mg + prednisolone 5 mg daily. AAP duration depended on stage and intent to give radical RT. The primary outcome measure was death from any cause. Analyses used Cox proportional hazards and flexible parametric models, adjusted for stratification factors. This was not a formally powered comparison. A hazard ratio (HR) <1 favours SOC + AAP, and HR > 1 favours SOC + DocP. Results: A total of 566 consenting patients were contemporaneously randomised: 189 SOC + DocP and 377 SOC + AAP. The patients, balanced by allocated treatment were: 342 (60%) M1; 429 (76%) Gleason 8-10; 449 (79%) WHO performance status 0; median age 66 years and median PSA 56 ng/ml. With median follow-up 4 years, 149 deaths were reported. For overall survival, HR = 1.16 (95% CI 0.82-1.65); failure-free survival HR = 0.51 (95% CI 0.39-0.67); progression-free survival HR = 0.65 (95% CI 0.48-0.88); metastasis-free survival HR = 0.77 (95% CI 0.57-1.03); prostate cancer-specific survival HR = 1.02 (0.70-1.49); and symptomatic skeletal events HR = 0.83 (95% CI 0.55-1.25). In the safety population, the proportion reporting ≥1 grade 3, 4 or 5 adverse events ever was 36%, 13% and 1% SOC + DocP, and 40%, 7% and 1% SOC + AAP; prevalence 11% at 1 and 2 years on both arms. Relapse treatment patterns varied by arm. Conclusions: This direct, randomised comparative analysis of two new treatment standards for hormone-naïve prostate cancer showed no evidence of a difference in overall or prostate cancer-specific survival, nor in other important outcomes such as symptomatic skeletal events. Worst toxicity grade over entire time on trial was similar but comprised different toxicities in line with the known properties of the drugs. Trial registration: Clinicaltrials.gov: NCT00268476.

Incorporating Biomarker Stratification into STAMPEDE: an Adaptive Multi-arm, Multi-stage Trial Platform.

The treatment and outcomes for advanced prostate cancer have experienced significant progress over recent years. Importantly, the additional benefits of 'up front' chemotherapy (docetaxel) and abiraterone, over and above conventional androgen deprivation, have been separately demonstrated in the multi-arm, multi-stage (MAMS) STAMPEDE protocol, which continues recruitment to other questions. Alongside this, insights into the underlying molecular biology and, inevitably, the molecular heterogeneity of prostate cancer are opening the door to new therapeutic approaches. Incorporating this understanding and testing these hypotheses within STAMPEDE brings new challenges to the MAMS approach, but has the potential to further improve the outlook for this disease.

UK Lung Cancer RCT Pilot Screening Trial: baseline findings from the screening arm provide evidence for the potential implementation of lung cancer screening.

BACKGROUND: Lung cancer screening using low-dose CT (LDCT) was shown to reduce lung cancer mortality by 20% in the National Lung Screening Trial. METHODS: The pilot UK Lung Cancer Screening (UKLS) is a randomised controlled trial of LDCT screening for lung cancer versus usual care. A population-based questionnaire was used to identify high-risk individuals. CT screen-detected nodules were managed by a pre-specified protocol. Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction. RESULTS: 247 354 individuals aged 50-75 years were approached; 30.7% expressed an interest, 8729 (11.5%) were eligible and 4055 were randomised, 2028 into the CT arm (1994 underwent a CT). Forty-two participants (2.1%) had confirmed lung cancer, 34 (1.7%) at baseline and 8 (0.4%) at the 12-month scan. 28/42 (66.7%) had stage I disease, 36/42 (85.7%) had stage I or II disease. 35/42 (83.3%) had surgical resection. 536 subjects had nodules greater than 50 mm(3) or 5 mm diameter and 41/536 were found to have lung cancer. One further cancer was detected by follow-up of nodules between 15 and 50 mm(3) at 12 months. The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening, under the UKLS protocol, was £8466 per quality adjusted life year gained (CI £5542 to £12 569). CONCLUSIONS: The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80% of cases. Health economic analysis suggests that the intervention would be cost effective-this needs to be confirmed using data on observed lung cancer mortality reduction. TRIAL REGISTRATION: ISRCTN 78513845.

Interim results in clinical trials: do we need to keep all interim randomised clinical trial results confidential?

OBJECTIVES: Guidelines for the conduct of clinical trials emphasize the importance of keeping the interim results from the main endpoints confidential, in order to maintain the integrity of the trial and to safeguard patients' interests. However, is this essential in every situation? MATERIALS AND METHODS: We review the evidence for these guidelines and consider recent randomised trials that have released interim results, to assess their impact on the success of the trial. However, because the strength of opinion to keep interim results confidential is so strong, there are limited examples of such trials. RESULTS: In the QUARTZ trial (which is assessing the value of whole brain radiotherapy in patients with brain metastases from non-small cell lung cancer) the decision to release interim results was taken in response to threatened closure due to poor accrual, whereas in the GRIT trial (which compared two obstetric strategies for the delivery of growth retarded pre-term fetuses) the regular release of interim results was pre-planned. Nevertheless there are a number of common factors between these two trials. In particular, the trial treatments were already in wide use, with no reliable randomised evidence on which treatment should be used for which patients, and there was diverse clinical opinion, which meant that accrual was likely to be challenging. In a situation where a quarter to a third of trials do not accrue their required number of patients, the QUARTZ trial continues to accrue patients, and the GRIT trial successfully accrued its target of nearly 600 babies. CONCLUSIONS: This article therefore argues that there is a need to re-consider whether it is always essential to keep the interim results of randomized clinical trials confidential, and suggests some criteria that may help groups planning or running challenging trials decide whether releasing interim results would be a useful strategy.

No socioeconomic inequalities in ovarian cancer survival within two randomised clinical trials.

BACKGROUND: Ovarian cancer is the leading cause of death among cancers of the female genital tract, with poor outcomes despite chemotherapy. There was a persistent socioeconomic gradient in 1-year survival in England and Wales for more than 3 decades (1971-2001). Inequalities in 5-year survival persisted for more than 20 years but have been smaller for women diagnosed around 2000. We explored one possible explanation. METHODS: We analysed data on 1406 women diagnosed with ovarian cancer during 1991-1998 and recruited to one of two randomised clinical trials. In the second International Collaborative Ovarian Neoplasm (ICON2) trial, women diagnosed between 1991 and 1996 were randomised to receive either the three-drug combination cyclophosphamide, doxorubicin and cisplatin (CAP) or single-agent carboplatin given at optimal dose. In the ICON3 trial, women diagnosed during 1995-1998 were randomised to receive either the same treatments as ICON2, or paclitaxel plus carboplatin.Relative survival at 1, 5 and 10 years was estimated for women in five categories of socioeconomic deprivation. The excess hazard of death over and above background mortality was estimated by fitting multivariable regression models with Poisson error structure and a dedicated link function in a generalised linear model framework, adjusting for the duration of follow-up and the confounding effects of age, Federation of Gynecology and Obstetrics (FIGO) stage and calendar period. RESULTS: Unlike women with ovarian cancer in the general population, no statistically significant socioeconomic gradient was seen for women with ovarian cancer treated in the two randomised controlled trials. The deprivation gap in 1-year relative survival in the general population was statistically significant at -6.7% (95% CI (-8.1, -5.3)), compared with -3.6% (95% CI (-10.4, +3.2)) in the trial population. CONCLUSIONS: Although ovarian cancer survival is significantly lower among poor women than rich women in England and Wales, there was no evidence of an association between socioeconomic deprivation and survival among women with ovarian cancer who were treated and followed up consistently in two well-conducted randomised controlled trials. We conclude that the persistent socioeconomic gradient in survival among women with ovarian cancer, at least for 1-year survival, may be due to differences in access to treatment and standards of care.

Platinum versus platinum-combination chemotherapy in platinum-sensitive recurrent ovarian cancer: a meta-analysis using individual patient data.

BACKGROUND: The majority of women with ovarian cancer develop recurrent disease. For patients with a platinum-free interval of >6 months, platinum-based chemotherapy is a treatment of choice. The benefit of platinum-based combination chemotherapy in randomized trials varies, and a meta-analysis was carried out to gain more secure information on the size of the benefit of this treatment. MATERIALS AND METHODS: We initiated a systematic review and meta-analysis following a pre-specified protocol to determine whether combination chemotherapy is superior to single-agent platinum chemotherapy in women with relapsed platinum-sensitive ovarian cancer. RESULTS: A total of five potentially eligible randomized trials were identified that had used combination-platinum chemotherapy versus single-agent platinum chemotherapy in women with relapsed platinum-sensitive ovarian cancer. For one trial (190 patients), adequate contact with the investigators could not be established. Therefore, four trials that randomly assigned 1300 patients were included, with a median follow-up of 36.1 months. Overall survival (OS) analyses were based on 865 deaths and demonstrated evidence for the benefit of combination-platinum chemotherapy (HR = 0.80; 95% CI, 0.64-1.00; P = 0.05). Progression-free survival (PFS) analyses were based on 1167 events and demonstrated strong evidence for the benefit of combination-platinum chemotherapy (HR = 0.68; 95% CI, 0.57-0.81; P < 0.001). There was no evidence of a difference in the relative effect of combination-platinum chemotherapy on either OS or PFS in patient subgroups defined by previous paclitaxel (Taxol) treatment (OS, P = 0.49; PFS, P = 0.66), duration of treatment-free interval (OS, P = 0.86; PFS, P = 0.48) or the number of previous lines of chemotherapy (OS, P = 0.21; PFS, P = 0.27). CONCLUSIONS: In this individual patient data (IPD) meta-analysis, we have demonstrated that combination-platinum chemotherapy improves OS and PFS across all subgroups. This provides the strongest evidence to date of the benefit of combination-platinum over single-agent platinum.

Interim data from the Medical Research Council QUARTZ Trial: does whole brain radiotherapy affect the survival and quality of life of patients with brain metastases from non-small cell lung cancer?

AIMS: Over 30% of patients with non-small cell lung cancer (NSCLC) develop brain metastases. If inoperable, optimal supportive care (OSC), including steroids, and whole brain radiotherapy (WBRT) are generally considered to be standard care, although there is no randomised evidence demonstrating that the addition of WBRT to OSC improves survival or quality of life. MATERIALS AND METHODS: QUARTZ is a randomised, non-inferiority, phase III trial comparing OSC + WBRT versus OSC in patients with inoperable brain metastases from NSCLC. The primary outcome measure is quality-adjusted life years (QALYs). QUARTZ was threatened with both loss of funding and early closure due to poor accrual. A lack of preliminary randomised data supporting the trial's hypotheses was thought to underlie the poor accrual, so, with no knowledge of the data, the independent trial steering committee agreed to the unusual step of releasing interim data. RESULTS: Between March 2007 and April 2010, 151 (of the planned 534) patients were randomised (75 OSC + WBRT, 76 OSC). Participants' baseline demographics included median age 67 years (interquartile range 62-73), 60% male, 50% with a Karnofsky performance status <70; steroid usage was similar in the two groups; 64/75 (85%) received WBRT (20 Gy in five fractions). Median survival was: OSC + WBRT 49 days (95% confidence interval 39-61), OSC 51 days (95% confidence interval 27-57) - hazard ratio 1.11 (95% confidence interval 0.80-1.53) in favour of WBRT. Quality of life assessed using EQ-5D showed no evidence of a difference. The estimated mean QALYs was: OSC + WBRT 31 days and OSC 30 days, difference -1 day (95% confidence interval -12.0 to +13.2 days). CONCLUSION: These interim data indicate no early evidence of detriment to quality of life, overall survival or QALYs for patients allocated to OSC alone. They provide key information for discussing the trial with patients and strengthen the argument for continuing QUARTZ to definitively answer this important clinical question.

Initial toxicity assessment of ICON6: a randomised trial of cediranib plus chemotherapy in platinum-sensitive relapsed ovarian cancer.

BACKGROUND: Cediranib is a potent oral vascular endothelial growth factor (VEGF) signalling inhibitor with activity against all three VEGF receptors. The International Collaboration for Ovarian Neoplasia 6 (ICON6) trial was initiated based on evidence of single-agent activity in ovarian cancer with acceptable toxicity. METHODS: The ICON6 trial is a 3-arm, 3-stage, double-blind, placebo-controlled randomised trial in first relapse of platinum-sensitive ovarian cancer. Patients are randomised (2 : 3 : 3) to receive six cycles of carboplatin (AUC5/6) plus paclitaxel (175 mg m(-2)) with either placebo (reference), cediranib 20 mg per day, followed by placebo (concurrent), or cediranib 20 mg per day, followed by cediranib (concurrent plus maintenance). Cediranib or placebo was continued for 18 months or until disease progression. The primary outcome measure for stage I was safety, and the blinded results are presented here. RESULTS: Sixty patients were included in the stage I analysis. A total of 53 patients had received three cycles of chemotherapy and 42 patients had completed six cycles. In all, 19 out of 60 patients discontinued cediranib or placebo during chemotherapy because of adverse events/intercurrent illness (n=9); disease progression (n=1); death (n=3); patient decision (n=1); administrative reasons (n=1); and multiple reasons (n=4). Grade 3 and 4 toxicity was experienced by 30 (50%) and 3 (5%) patients, respectively. No gastrointestinal perforations were observed. CONCLUSION: The addition of cediranib to platinum-based chemotherapy is sufficiently well tolerated to expand the ICON6 trial and progress to stage II.

Aspirin and cancer: has aspirin been overlooked as an adjuvant therapy?

Aspirin inhibits the enzyme cyclooxygenase (Cox), and there is a significant body of epidemiological evidence demonstrating that regular aspirin use is associated with a decreased incidence of developing cancer. Interest focussed on selective Cox-2 inhibitors both as cancer prevention agents and as therapeutic agents in patients with proven malignancy until concerns were raised about their toxicity profile. Aspirin has several additional mechanisms of action that may contribute to its anti-cancer effect. It also influences cellular processes such as apoptosis and angiogenesis that are crucial for the development and growth of malignancies. Evidence suggests that these effects can occur through Cox-independent pathways questioning the rationale of focussing on Cox-2 inhibition alone as an anti-cancer strategy. Randomised studies with aspirin primarily designed to prevent cardiovascular disease have demonstrated a reduction in cancer deaths with long-term follow-up. Concerns about toxicity, particularly serious haemorrhage, have limited the use of aspirin as a cancer prevention agent, but recent epidemiological evidence demonstrating regular aspirin use after a diagnosis of cancer improves outcomes suggests that it may have a role in the adjuvant setting where the risk:benefit ratio will be different.

A critical review of methods for the assessment of patient-level interactions in individual participant data meta-analysis of randomized trials, and guidance for practitioners.

OBJECTIVE: Treatments may be more effective in some patients than others, and individual participant data (IPD) meta-analysis of randomized trials provides perhaps the best method of investigating treatment-covariate interactions. Various methods are used; we provide a comprehensive critique and develop guidance on method selection. STUDY DESIGN AND SETTING: We searched MEDLINE to identify all frequentist methods and appraised them for simplicity, risk of bias, and power. IPD data sets were reanalyzed. RESULTS: Four methodological categories were identified: PWT: pooling of within-trial covariate interactions; OSM: "one-stage" model with a treatment-covariate interaction term; TDCS: testing for difference between covariate subgroups in their pooled treatment effects; and CWA: combining PWT with meta-regression. Distinguishing across- and within-trial information is important, as the former may be subject to ecological bias. A strategy is proposed for method selection in different circumstances; PWT or CWA are natural first steps. The OSM method allows for more complex analyses; TDCS should be avoided. Our reanalysis shows that different methods can lead to substantively different findings. CONCLUSION: The choice of method for investigating interactions in IPD meta-analysis is driven mainly by whether across-trial information is considered for inclusion, a decision, which depends on balancing possible improvement in power with an increased risk of bias.

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.