EFFECT OF THORACIC RADIOTHERAPY ON MORTALITY IN LIMITED SMALL-CELL LUNG-CANCER - A METAANALYSIS OF 13 RANDOMIZED TRIALS AMONG 2,140 PATIENTS

This meta-analysis was designed to evaluate the hypothesis that thorac ic radiotherapy contributes to a moderate increase in overall survival in limited small-cell lung cancer. We collected individual data on al l patients enrolled before December 1988 in randomized trials comparin g chemotherapy alone with chemotherapy combined with thoracic radiothe rapy. The study included 13 trials and 2140 patients with limited dise ase. A total of 433 patient with extensive disease were excluded. Over all, 1862 of 2103 patients who could be evaluated died; the median fol low-up period for the surviving patients was 43 months. The relative r isk of death in the combined therapy group as compared with the chemot herapy group was 0.86 (95 percent confidence interval, 0.78 to 0.94, P = 0.001), corresponding to a 14 percent reduction in the mortality rat e. The benefit in terms of overall survival at three years (+/-SD) was 5.4 +/- 1.4 percent. Indirect comparison of early with late radiother apy and of sequential with nonsequential radiotherapy did not reveal a ny optimal time for treatment. There was a trend toward a larger reduc tion in mortality among younger patients. in conclusion, thoracic radi otherapy moderately improves overall survival in patients with limited small-cell lung cancer who are treated with combination chemotherapy.