Did You Know?

Mesothelioma has a long latency (inactive) period of anywhere between 15 – 50 years.

Once the diagnosis of malignant mesothelioma has been confirmed, the next step is determining the extent of the disease (called staging). Imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI), allow physicians to assess the stage of the disease and determine the most appropriate treatment. The staging system used in the past for mesothelioma is the Butchart System. This system is based mainly on the extent of the primary tumor mass, and divides mesotheliomas into stages I through IV. Many doctors will still use this system. Staging defines how far the cancer has spread from its original location to other parts of the body.

The stages of malignant mesothelioma are:

•  Stage I - The tumor is found in the pleura with or without some involvement of the lung, pericardium (lining of the heart) or diaphragm.
•  Stage II - The tumor is found in a stage I location, plus there is involvement of some lymph nodes in the chest.
•  Stage III - The tumor has extended into the chest wall, ribs or heart, through the diaphragm or into the peritoneum (the abdominal lining). There also may be involvement of the lymph nodes.
•  Stage IV - The tumor has spread through the bloodstream to distant sites (that is, it has metastasized).
•  Recurrent mesothelioma - The tumor has recurred after treatment.

Stage I also is called localized disease, whereas stages II to IV are called advanced disease. Stage I disease generally has the best prognosis, particularly when the tumor is of the epithelial type.

If the diagnosis is mesothelioma, your doctor will need to know the stage of your disease. Staging can be clinical or pathological. Clinical staging relies on scanning tests and x-rays. Pathological staging refers to staging done at surgery.

Malignant mesothelioma moves through four stages, each one more serious than the next. The cancer is described as localized if it is found only on the lining surface where it originated. If the cancer has spread beyond the original site to other parts of the body, such as the lymph nodes, chest wall, or abdominal organs, it is considered as advanced.

The stage of the cancer will determine treatment options and helps determine the prognosis of the disease. Pleural mesothelioma is the only mesothelioma that has a staging system. But the clinical staging systems are considered inadequate due to the way the disease spreads.

Other Mesothelioma Staging Systems

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

Mesothelioma Help Center is not designed to provide medical advice or is intended to be for educational use only. The information provided through Mesothelioma Help Center is not a substitute for professional care and should not be used for diagnosing or treating a health problem or a disease. If you have, or suspect you may have, a health problem we can refer you to a mesothelioma doctor or lawyer in your state.