Treatment options offered to patients are decided on a case-by-case basis and are dependent on the stage of mesothelioma. Likewise, the survival rate of the disease is also dependent on its development stage and reduces significantly in the last stages. Staging refers to the extent of the cancer developments within patients and is characterized by the kind of tumor and the degree to which it has spread throughout the body. With the knowledge of the various stages, the mesothelioma specialists are able to decide on a treatment plan and identify clinical trials for them. The type or treatment also depends on the reason for the development of the cancer, the kind of tumor, its propensity for invasion of nearby organs and tissues as well as the distant spread or metastatic to other body parts.