The Mesothelioma and Radical Surgery Randomized Controlled Trial: The MARS Feasibility Study

Hypothesis:The effectiveness of extrapleural pneumonectomy (EPP) to extend quality-adjusted survival in malignant pleural mesothelioma within multimodality treatment should be proven in a randomized controlled trial if this radical surgery is to be regarded as the standard of care. The question was whether randomization to surgery versus no surgery would be possible.Methods:The Mesothelioma and Radical Surgery trial was planned to randomize 50 patients to test feasibility. There was a two-stage consent process. At first consent, the patients who were possible candidates for radical surgery were registered into the trial for completion of assessment and staging. All received platinum-based chemotherapy. If still eligible, they completed a second consent to be randomized to have either EPP followed by radical hemithorax radiotherapy or to have continued best care.Results:Patients were recruited through 11 collaborating centers in the United Kingdom. One hundred twelve potentially eligible patients gave informed consent to enter the registration phase and undergo chemotherapy. One died, 27 progressed, five were inoperable, four were treated off trial, and 18 withdrew either during or after chemotherapy but before final review. Additionally six were deemed inoperable at review after completing chemotherapy and one more patient withdrew. The remaining 50 were randomized; 24 to EPP and 26 to continued best care.Conclusions:In this study, 50/112 (45%) of patients entering the evaluation and induction phase of the trial went on to be randomized. We have shown that this randomization between surgery and no surgery is feasible. This was the primary aim of the Mesothelioma and Radical Surgery trial.