MARS Trial: Mesothelioma and Radical Surgery

The chief research question the MARS trial asks is whether radical surgery can cure mesothelioma or at least sufficiently improve the length and quality of patients’ lives more than less aggressive treatment or none at all.

This trial opened for recruiting in August 2005 and seeks to recruit 50 patients into the pilot study. As of January 2007, it was predicted that the recruiting goal would be reached by the end of 2007; however more current information regarding the status of the trial proceedings is not yet available. In the study design, all 50 patients undergo three cycles of chemotherapy before further treatment is given. After chemotherapy, researchers again assess the staging of the patients’ tumors, and then randomly assign a treatment of radical surgery and radiotherapy or no radical surgery. Patients not assigned to radical surgery may still receive less aggressive tumor debulking surgery and radiotherapy when deemed appropriate.

If the outcomes of the pilot study shows the trial is acceptable and the treatment is tolerable, the study will be expanded to a wider-scale, international level and will analyze survival and quality of life outcomes.

Currently, radical surgery is popularly viewed as the best treatment option for patients with operable mesothelioma and in good overall health. Until recently an extrapleural pneumonectomy was the preferred surgical treatment. The “EPP” is the radical surgery given in the MARS trial, in which one entire lung on the affected side of the chest is removed. Another less radical surgery option is the pleurectomy with decortication, in which the healthy lungs are spared but the tumor and any compromised organ linings are removed. However, the MARS study will not include this surgical procedure in its variable design.

In addition to surgery, adjuvant therapies are typically considered beneficial to survival outcomes. With a multi-modal approach, patients may receive chemotherapy before or after surgery and generally undergo radiation treatment after surgery. These additional treatments aim to destroy any remaining cancer cells to prevent local recurrence or distant metastases of the cancer. The MARS trial will use both chemotherapy and radiation therapy on both treatment groups.

The MARS trial is a significant step for mesothelioma research. There is presently no standard regimen of care for this disease, because there has been insufficient research to prove the efficacy of available treatments. The most significant limitation of past studies has been that they are not randomized clinical trial designs. Most have been retrospective case-control studies or cohorts. A randomized clinical trial is the only truly experimental design, which allows investigators to administer treatment and compare outcomes with a control group. The MARS trial will have a radical treatment group and a control group, and will thus render the results of the study to be more scientifically valid and authoritative.