Chemotherapy for carcinoma of the esophagus: A comparison of evidence from meta-analyses of randomized trials and of historical control studies

Abstract

Background: Chemotherapy (CT) has been used as an adjunct to local treatment (surgery or radiotherapy) in esophageal carcinoma. A meta-analysis 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 cancer. Materials and methods: A computer-based literature search was performed for the period from January 1988 to March 1995 using the index terms 'Esophageal neoplasms' and 'Chemotherapy: The frame of reference was further narrowed to include only cisplatinum-based combination chemotherapy. Twelve randomized clinical trials (RCT) and eight historical control (HC) studies were included in the meta-analysis. Results: In the overview of HC studies a highly significant reduction in odds of 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 in 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 of cisplatinum-based chemotherapy in both groups. The meta-analysis of RCTs reveal no significant survival benefit from cisplatinum-based adjuvant/neoadjuvant chemotherapy in esophageal cancer.