SummaryBackgroundMany 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.MethodsWe 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.FindingsThe 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.InterpretationThe 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.FundingUK Medical Research Council, Institut Gustave-Roussy, Programme Hospitalier de Recherche Clinique (AOM 05 209), Ligue Nationale Contre le Cancer, and Sanofi-Aventis.

Summary The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin-or carboplatinbased therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than nonplatinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients.Keywords: meta-analysis; systematic review; randomized controlled trials; advanced ovarian cancer; chemotherapy Health care professionals and patients alike are becoming increasingly aware of the need to make medical decisions on the basis of up-to-date, objective and unbiased research (Chalmers and Haynes, 1994). The most reliable information results from randomized controlled trials (RCTs). Unfortunately, most RCTs, including those conducted in ovarian cancer, have been too small to demonstrate moderate treatment benefits with reliability, and many results have been inconclusive or contradictory. The Advanced Ovarian Cancer Trialists Group (AOCTG) recognized that the best means of synthesizing such randomized evidence is by systematic meta-analysis. In 1988, five meta-analyses of chemotherapy in advanced ovarian cancer using updated individual patient data were initiated. The first results were published in 1991 (AOCTG, 1991). The AOCTG recognized the importance of updating these results especially for the comparison of carboplatin and cisplatin, in which the data were relatively immature. The comparison of platinum analogues was considered of such clinical importance that further new investigations were initiated to identify whether any particular type of women or tumour would benefit more from either cisplatin-or carboplatin-based chemotherapy. PATIENTS AND METHODSTrials were eligible for inclusion provided they examined first-line chemotherapy for advanced ovarian cancer, were properly randomized and made one of the treatment comparisons described below. Trials were identified by bibliographic searches using MEDLINE and CancerLit, by hand searching relevant meeting proceedings and by consulting trial registers (AOCTG, 1991). Both published and unpublished trials were included and updated data were sought for all randomized patients. All data were checked thoroughly and the final database entries for each trial were verified by the responsible trialist or data centre.All analyses were based on intention to treat. Survival analyses were stratified by trial, and t...

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Four large randomised trials of paclitaxel in combination with platinum against a platinum-based control treatment have now been published in full, representing around 88% (3588 out of 4057) of patients randomised into the eight known trials of this question. There is substantial heterogeneity in the results of these four trials. Four main explanations for this heterogeneity have been proposed: differences in the extent and timing of 'crossover' to taxanes in the control groups; differences in the types of patient included; differences in the effectiveness of the research regimens used; differences in the effectiveness of the control regimens used. In this study we examine whether any of these explanations is consistent with the pattern of results seen in these trials. Each explanation suggests that a particular characteristic of each trial was responsible for the results observed. For each explanation the trials were split into groups according to that characteristic, in order to partition the total heterogeneity into that seen 'within' and 'between' groups of trials. If a particular explanation was consistent with the pattern of results, we would expect to see relatively little heterogeneity within each group of trial results viewed in this way, with most of the heterogeneity being between groups which are dissimilar with respect to the key characteristic. Heterogeneity 'within' and 'between' groups was formally compared using the F-ratio. If any explanation appeared to be consistent with the results of the trials, it was considered whether the explanation was also consistent with other evidence available about these regimens. Only one explanation appeared to be consistent with the pattern of results seen in these trials, and that was differences in effectiveness of the control arms used in these trials. This suggests that the very positive results in favour of paclitaxel/cisplatin seen in two of the trials may have been due to the use of a suboptimal control arm. There is no direct evidence about the relative effectiveness of the control arms used in these trials, but indirect evidence is consistent with the conclusion that the cyclophosphamide/cisplatin regimen used in two of the trials may be less effective than the control regimens used in the other trials. Specific concerns about the choice of a cyclophosphamide/cisplatin control arm in the first of these trials to report were raised before the results of the other trials were known, i.e. before any heterogeneity had been observed. Further investigation of this question would be useful. In the meantime, given all of the randomised evidence on the efficacy and toxicity associated with the regimens used in these trials, we conclude that single agent carboplatin is a safe and effective first-line treatment for women with advanced ovarian cancer.

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