Mixed treatment comparison meta-analysis of altered fractionated radiotherapy and chemotherapy in head and neck cancer.

OBJECTIVE: Different treatments have been investigated in head and neck cancers (HNCs) but not all of them have been appraised using pairwise comparison. This has resulted in failure to directly identify the best treatment with standard methods. Mixed treatment comparison (MTC) meta-analysis allows one to perform simultaneous inference regarding all treatments and select the best among them. STUDY DESIGN AND
SETTING: We applied MTC models to the Meta-Analyses of Chemotherapy and Radiotherapy in HNC, which pooled individual patient data concerning more than 24,000 patients involved in 102 trials. Fixed- and random-effects models, models with or without consistency factors, possibly adapted to multiarm trials are discussed.
RESULTS: Altered fractionated concomitant chemoradiotherapy (AF-CRT) leads to the highest probability of survival in nonmetastatic HNC. The probability that AF-CRT is the best treatment is 94% with random-effects models. There was no relevant inconsistency. When only the most recent trials were selected, AF-CRT and concomitant chemoradiotherapy (CRT) were the two best treatments. AF-CRT remains better than CRT but with a lower posterior probability.
CONCLUSION: MTC is a powerful method for investigating networks of randomized trials. Homogeneity, similarity of trial designs, populations, and the consistency of the network should be thoroughly checked.