The authors reflect on the need for randomized controlled trials (RCTs) in the use of radiotherapy for malignant pleural mesothelioma (MPM) in London, England. They noted that the Mesothelioma and Radical Surgery (MARS), an RCT of extrapleural pneumonectomy (EPP) followed by radiotherapy, has proven that such trials are feasible. They emphasize that the use of RCT can ensure a fair comparison and can protect against unwarranted optimism in recall of the data.