Postoperative radiotherapy for non-small cell lung cancer.

BACKGROUND The role of postoperative radiotherapy in the treatment of patients with completely resected non-small cell lung cancer was not clear. A systematic review and quantitative meta-analysis was therfore undertaken to evaluate the available evidence from randomised trials. OBJECTIVES To evaluate the effect of post-operative radiotherapy (PORT) on survival and recurrence in patients with completely resected non-small cell lung cancer. To investigate whether or not pre-defined patient sub-groups benefit more or less from PORT. SEARCH STRATEGY MEDLINE and CANCERLIT searches were supplemented by information from trial registers and by hand searching relevant meeting proceedings and by discussion with relevant trialists and organisations. SELECTION CRITERIA Both published and unpublished trials were eligible for inclusion provided the patients had undergone a complete resection; had been randomised between radiotherapy and no immediate further treatment; that the method of randomisation precluded prior knowledge of the treatment to be assigned; and that recruitment was between 1965 and 1995. DATA COLLECTION AND ANALYSIS A quantitative meta-analysis using updated information from individual patients from all available randomised trials was carried out. Data from all patients randomised in all eligible trials were sought directly from those responsible. Updated information on survival, recurrence and date of last follow up were obtained, as were details of treatment allocated, date of randomisation, age, sex, histological cell type, stage and performance status. To avoid potential bias, information was requested for all randomised patients including those who had been excluded from the investigators' original analyses. All analyses were done on intention to treat on the endpoints of survival and recurrence-free survival. Subgroup analyses by age, sex, histological cell type, tumour stage and performance status were also done. MAIN RESULTS 2128 patients from 9 trials were included (median follow-up of 3.9 years). The results show a significant adverse effect of PORT on survival with a hazard ratio of 1.21 or 21% relative increase in the risk of death. This is equivalent to an absolute detriment of 7% at 2 years (95% confidence interval 3 to 11%) reducing overall survival from 55% to 48%. Exploratory subgroup analyses suggested that this detrimental effect was most pronounced for patients with stage I/II, N0-N1 disease, whereas for stage III, N2 patients there was no clear evidence of an adverse effect. REVIEWER'S CONCLUSIONS PORT is detrimental to patients with early stage completely resected non-small cell lung cancer and should not be used in the routine treatment of such patients. The role of PORT in the treatment of N2 tumours is not clear and may justify further research.