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

Abstract

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.