CHEMOTHERAPY FOR CARCINOMA OF THE ESOPHAGUS - A COMPARISON OF EVIDENCE FROM METAANALYSES OF RANDOMIZED TRIALS AND OF HISTORICAL CONTROL STUDIES

Background: Chemotherapy (CT) has been used as an adjunct to local tre atment (surgery or radiotherapy) in esophageal carcinoma. A meta-analy sis of all published randomized clinical trials and historical control studies which have used cisplatinum-based combination CT was carried out to asses the effect of chemotherapy on survival for esophageal can cer. Materials and methods: A computer-based literature search was per formed for the period from January 1988 to March 1995 using the index terms 'Esophageal neoplasms' and 'Chemotherapy'. The frame of referenc e was further narrowed to include only cisplatinum-based combination c hemotherapy. Twelve randomized clinical trials (RCT) and eight histori cal control (HC) studies were included in the meta-analysis. Results: In the overview of HC studies a highly significant reduction in odds o f death with CT was observed (68% +/- 8% OR = 0.32, 95% CI 0.24-0.42). On the other hand, the overview of RCTs showed a relative reduction i n odds of death for the CT group of 4.2% +/- 23.7% (OR = 0.96, 95% CI 0.75-1.22). Conclusions: There was a gross overestimation of treatment effect in the studies using HC as compared to RCTs, despite the use o f cisplatinum-based chemotherapy in both groups. The meta-analysis of RCTs reveal no significant survival benefit from cisplatinum-based adj uvant/neoadjuvant chemotherapy in esophageal cancer.