Meta-analysis of chemotherapy versus combined modality treatment trials in Hodgkin's disease. International Database on Hodgkin's Disease Overview Study Group.

DESIGNTo perform a meta-analysis of all randomized trials that compared chemotherapy (CT) alone versus combined modality treatment (CT + radiotherapy [RT]) for which individual patient data could be made available.PATIENTS AND METHODSData on 1,740 patients treated on 14 different trials that included 16 relevant comparisons have been analysed. Eight comparisons were designed to evaluate the benefit of additional RT after the same CT (CT1 v CT1 + RT; additional RT design). Eight comparisons were designed to evaluate whether RT in a combined modality setting can be substituted by CT using either more cycles of the same CT or regimens that contain additional drugs (CT1 + CT2 v CT1 + RT or CT1 v CT2 + RT; parallel RT/CT design).RESULTSAdditional RT showed an 11% overall improvement in tumor control rate after 10 years (P = .0001; 95% confidence interval [CI], 4% to 18%). No difference could be detected with respect to overall survival (P = .57; 95% CI, -10% to 4%). In contrast, when combined modality treatmen...