Mesothelioma Stages

Stage is the term used to describe the extent of a patient's cancer, based on the primary tumor and its spread in the body. It can help the medical team plan treatment, estimate prognosis and identify clinical trials for which the patient may be eligible. Staging system has been developed by oncologists for several decades. Mesothelioma stages determine the treatment options for the patients. Staging is used only for pleural mesothelioma. Peritoneal, pericardial and testicular mesothelioma is not staged.
Staging is based on a knowledge of how the cancer develops, from the primary tumor, to the invasion of nearby organs and tissues, to distant spread or metastasis. Staging systems have evolved over time, and they continue to change as scientists learn more about cancer and tumor. Some staging systems cover many different types of cancer, while others focus on more specific cancers. The most common staging system is TNM (primary tumor, regional lymph nodes, distant metastasis).
The staging systems using elements such as location of the primary tumor, Size of tumor, number of the tumors, cell type, tumor grade, lymph node involvement, metastasis.
To determine the stage and to formulate the treatment plan, some testing types are used, such as :
• imaging test (X-Rays, CT scans, MRI, PET scan that shows the location, size and cancer spread)
• Laboratory tests (studies of blood, urine, fluid and tissue can provide information about the cancer)
• Physical examination tests.
• Pathology tests. (tissue sample can provide information about tumor size and structure, type of cells, tumor grade, etc.
• Surgical reports. (The report of observation about the size and appearance of the tumors, lymph nodes and nearby organs)
Stages, patient’s age, health status, and other factors determine the treatment options for the patients.

There are three staging system

Butchart System – extent of primary tumor mass
• Stage I: Mesothelioma is present in the right or left pleura and may also involve the diaphragm on the same side.
• Stage II: Mesothelioma invades the chest wall or involves the esophagus, heart, or pleura on both sides. Lymph nodes in the chest may also be involved.
• Stage III: Mesothelioma has penetrated through the diaphragm into the lining of the abdominal cavity or peritoneum. Lymph nodes beyond those in the chest may also be involved.
• Stage IV: There is evidence of metastasis or spread through the bloodstream to other organs.

TNM System -- variables of T (tumor), N (lymph nodes), M (metastasis)
• Stage I: Mesothelioma involves right or left pleura and may also have spread to the lung, pericardium, or diaphragm on the same side. Lymph nodes are not involved.
• Stage II: Mesothelioma has spread from the pleura on one side to nearby lymph nodes next to the lung on the same side. It may also have spread into the lung, pericardium, or diaphragm on the same side.
• Stage III: Mesothelioma is now in the chest wall, muscle, ribs, heart, esophagus, or other organs in the chest on the same side with or without spread to lymph nodes on the same side as the primary tumor.
• Stage IV: Mesothelioma has spread into the lymph nodes in the chest on the side opposite the primary tumor, or extends to the pleura or lung on the opposite side, or directly extends into organs in the abdominal cavity or neck. Any distant metastases is included in this stage.

Brigham System: (variables of tumor resectability and nodal status)
• Stage I: Resectable mesothelioma and no lymph node involvement
• Stage II: Resectable mesothelioma but with lymph node involvement
• Stage III: Unresectable mesothelioma extending into chest wall, heart, or through diaphragm, peritoneum; with or without extrathoracic lymph node involvement
• Stage IV: Distant metastatic disease

The oldest staging system and the one most often used is the Butchart System which is based mainly on the extent of primary tumor mass and divides mesotheliomas into four stages. The more recent TNM system considers variables of tumor in mass and spread, lymph node involvement, and metastasis. The Brigham System is the latest system and stages mesothelioma according to resectability (the ability to surgically remove) and lymph node involvement.