How is malignant mesothelioma staged?

Staging is the way that doctors summarize how far mesothelioma has spread. Staging is important because your treatment and prognosis depends on it. Patients with lower stage numbers tend to have a better prognosis. The stage of a mesothelioma is based on the results of physical exams, biopsies, and imaging tests. Pleural mesothelioma is the only mesothelioma for which a formal staging system actually exists. Below is a description of the various stages for pleural mesothelioma.

Stage I

Mesothelioma has grown:

  • Into the pleura lining on one side of the chest

Mesothelioma may have grown:

  • Into the diaphragm (the breathing muscle) or the mediastinum (the space between the lungs)

Mesothelioma has not:

  • Spread to the lymph nodes or to distant sites

Stage II

Mesothelioma has grown:

  • Into the pleura lining on one side of the chest
  • In the pleura coating the diaphragm, the mediastinum, and the lung
  • Into the diaphragm or the lung itself

Mesothelioma has not:

  • Spread to the lymph nodes or to distant sites

Stage III

Either of the following:

Mesothelioma has grown:

  • Into the pleura lining of the chest on one side
  • Into lymph nodes in the chest on the same side as the main tumor

Mesothelioma may have grown:

  • Into the pleura lining the lung, the diaphragm, or the mediastinum
  • Into the muscle of the diaphragm or the lung itself

Mesothelioma has not:

  • Spread to distant sites

OR

Mesothelioma has grown:

  • Into the pleura lining of the chest on one side
  • Into the first layer of the chest wall
  • Into the mediastinum or the outer covering layer of the heart

Mesothelioma may have grown:

  • Into the lymph nodes in the chest on the same side as the tumor

Mesothelioma has not:

  • Spread to lymph nodes near the collarbone or on the opposite side of the chest. It has not spread to distant sites

Stage IV

Any of the following:

Mesothelioma has grown into:

  • The pleura lining
  • More than one place in the deeper layers of the chest wall
  • The diaphragm and into the peritoneum
  • Any organ in the mediastinum
  • The spine
  • The pleura on the other side of the chest, and/or through the heart lining or into the heart itself

Mesothelioma may have grown:

  • And spread to lymph nodes

Mesothelioma has not:

  • Spread to distant sites

OR

Mesothelioma has grown into:

  • Lymph nodes near the collarbone on either side and/or to hilar or mediastinal lymph nodes on the side opposite the main tumor

Mesothelioma may have grown:

  • Into nearby tissues.

Mesothelioma has not:

  • Spread to distant sites

OR

Mesothelioma may have grown:

  • Into nearby tissues
  • Into the lymph nodes

Mesothelioma has grown into:

  • And spread to distant sites