Mesothelioma is a cancer of the thin membrane that lines the chest and abdomen. Around 2300 people in the UK are diagnosed with mesothelioma each year and the average survival is approximately 17 months. Exposure to asbestos is the most common cause although the cancer does not usually become apparent until 30-40 years after exposure. Anti-cancer drugs (chemotherapy) are usually given to help treat mesothelioma and sometimes lung-sparing surgery (pleurectomy decortication) surgery is undertaken. However, it is not known if this surgery, in addition to chemotherapy, can increase survival and improve the quality of life for patients. The aim of the MARS2 study is to determine if it is feasible to enrol patients with mesothelioma into a study randomising them to chemotherapy only or chemotherapy and lung-sparing surgery. Patients will be followed up regularly at their usual clinic visits for to 5 years. Patients will be asked to complete a Quality of Life Questionnaire at these visits. Tissue samples will be taken at the time of diagnosis and at surgery (if they are randomised to surgery) for mesothelioma research central storage and blood samples will be taken at the clinic visits up to 12 months for mesothelioma research central storage. If we can show the feasibility of recruitment we will apply to continue the study to include more patients in order to determine if lung-sparing surgery improves survival and quality of life for mesothelioma patients.