Chemotherapy and radiation therapy as compared with radiation therapy in stage III non-small-cell cancer

Trials with mitomycin, ifosfamide and cisplatin in non-small cell lung cancer

In 1988, we reported a Phase II study of mitomycin, ifosfamide and cisplatin (MIC) in inoperable non-small cell lung cancer. The overall objective response rate was 56% in 66 evaluable cases. An improvement in performance status was observed in responding patients and toxicity was acceptable. Consequently we then embarked upon two major, multicentre randomised trials to test this regimen in cases with localised disease (MIC 1--chemotherapy plus radical radiotherapy versus radical radiotherapy alone) and advanced disease (MIC 2--chemotherapy plus palliative care versus palliative care alone). These trials are still in progress with targets of 500 and 300 randomised cases, respectively. The present interim analysis is based on 317 cases randomised in MIC 1 and 193 in MIC 2. The overall response rate (CR + PR) in the MIC 1 trial is 52% with 10% CRs and in the MIC 2 trial is 42% with 5% CRs. Formal symptomatic assessments are monitored in both trials and the present interim analysis indicates symptom improvement in cases randomised to chemotherapy, including patients who fail to achieve an objective PR or CR. Other Phase II studies employing MIC are also reviewed.

Adjuvant and neo-adjuvant chemotherapy in non-small cell carcinoma

BACKGROUND

There have been many trials investigating the influence of chemotherapy on survival following surgery or radiotherapy in non-small cell lung cancer. Few have been large enough to detect the sort of differences likely to emerge, given the limited efficacy of chemotherapy. The technique of meta-analysis using individual patient data can allow worthwhile conclusions to be derived from the contradictory data generated by multiple small trials. This paper summarizes published data from randomized trials testing: (1) adjuvant chemotherapy following 'curative' surgery; (2) neoadjuvant chemotherapy prior to surgery in cases of borderline operability; (3) chemotherapy in inoperable, but still localized, disease where standard therapy would be radical radiotherapy.

CONCLUSION

All the indications are that combinations including cisplatin confer a small, but real, prolongation of survival. However, meta-analysis is not a substitute for individual trials large enough to detect clinically important differences in survival. Other worthwhile endpoints like symptom control, quality of life and cost cannot be addressed in a meta-analysis. Large, well designed and executed randomized trials are still urgently needed if more time and money is not going to be wasted in the search for better treatments in lung cancer.

Stopping a clinical trial early: frequentist and Bayesian approaches applied to a CALGB trial in non-small-cell lung cancer

In May 1984, the Cancer and Leukemia Group B (CALGB) opened a phase III clinical trial for patients with stage III non-small-cell lung cancer (NSCLC). The experimental design entailed randomization of 240 patients equally to one of two treatments: radiotherapy alone or chemotherapy followed by radiotherapy. The original design was a fixed sample size design with the intent to analyse the results after 190 deaths. Shortly after the trial began, it was decided to apply group sequential concepts by using a truncated O'Brien-Fleming stopping rule, implemented via a Lan-DeMets alpha-spending function. A study monitoring committee was established to review the analyses as they were produced. The study was stopped at the fifth interim analysis in May 1987 after 155 eligible patients had been entered. This paper reviews the statistical and other considerations leading to this decision and presents later follow-up information on these patients. Some Bayesian alternatives to the standard frequentist approaches are also explored and it is demonstrated how these alternatives provide a natural way to address many of the issues raised in monitoring clinical trials.

Combined modality treatment for locally advanced non-small cell lung cancer--which control arm?

Up to one-third of newly diagnosed patients with non-small cell lung cancer (NSCLC) present with locally advanced, unresectable disease. Traditionally, these patients have been treated with thoracic radiotherapy alone. Unfortunately, the vast majority eventually die as a result of the development of distant, extrathoracic metastases. While chemotherapy is not particularly effective against clinically obvious metastatic disease, there are good theoretical reasons why the use of this modality in earlier stage disease may be beneficial. Several recently completed pilot studies of combined modality therapy have yielded promising results suggesting improved survival. Indeed, the combination of chemotherapy and thoracic radiotherapy has been shown to be marginally superior to radiotherapy alone in a few recently completed randomized trials. However, this has not been a uniform observation. Thus, further study is needed to firmly establish the role of combined modality treatment in Stage III, unresectable non-small cell lung cancer. In these future trials, the best control arm is a matter of some controversy.

Pitfalls and biases in the reporting and interpretation of the results of clinical trials

There are numerous biases (not all statistical) that can occur in the reporting and interpretation of the results of clinical trials. In this paper we review some of the major sources of such biases and propose some solutions for these problems. In particular, we review the biases that can occur in non-randomised studies; the effects of exclusion of patients after randomisation; reporting on the subset of patients receiving 'full' treatment only; comparing responders with non-responders; and emphasising secondary endpoints or subgroups. We also discuss the correct interpretation of a P-value and show the need for both estimates of the treatment effect and confidence intervals for reliable interpretation of the results. Finally, we consider the important but less well discussed problems of the interpretation of both classically 'negative' and 'positive' trials and the impact of the early stopping of the trial on the estimate of the treatment effect.

Statistics in medical journals: developments in the 1980s

This paper reviews changes in the use of statistics in medical journals during the 1980s. Aspects considered are research design, statistical analysis, the presentation of results, medical journal policy (including statistical refereeing), and the misuse of statistics. Despite some notable successes, the misuse of statistics in medical papers remains common.