Colorectal cancer patients presenting with pulmonary metastases will first be consented for registration into the study. This consent is to undergo evaluation according to the trial protocol as part of the work up for consideration by the MDT. Following evaluation, the MDT will consider how they would normally treat each patient according to their standard local practice. Patients eligible for randomisation will be those for whom clinical uncertainty exists as to whether surgery would be of benefit. This trial design was successful in a study of the feasibility of randomising patients in a trial of mesothelioma surgery.