Staging a cancer allows doctors to determine how far the cancer has advanced. Specific staging systems have been designed to stage various forms of cancer. These systems allow doctors to describe in a uniform, more accurate manner how advanced the disease is, so that treatment can be better tailored to the individual patient’s needs. A staging system has been designed for pleural mesothelioma because it occurs most frequently. The other forms of mesothelioma do not have a staging system.
The International Mesothelioma Interest Group has developed a staging system for pleural mesothelioma. This system is called the TNM system. It has been adopted by the American Joint Committee on Cancer (AJCC) and it is similar to the staging systems of other forms of cancer.
Pleural mesothelioma is staged by careful examination of imaging studies. TNM stands for the three determining classification stages in the system. ‘T’ designates tumor, ‘N’ denotes the lymph nodes, and ‘M’ represents metastasis (the spread of the cancer to other organs). There are four stages of mesothelioma; each stage is designated by a Roman numeral (I-IV). The information from the TMN classifications combined to determine what stage the cancer has advanced to. Stage I is the earliest stage of mesothelioma; the cancer is localized and has not advanced from its original outbreak site. Stage IV is the end stage of pleural mesothelioma; the cancer has advanced and spread to other organs making it impossible to remove.
Mesothelioma Stages
Within in the TNM system there are four tumor stages (T stages):
T1:Either the right or the left pleura lining (chest lining) is affected by the mesothelioma. The mesothelioma has spread to the lining covering the lung and possibly to a few other minute spots.
T2:At this stage the mesothelioma tumor is affecting one side of the chest, but it has spread into the lung’s outer lining, or the diaphragm, or the lung’s interior.
T3:By this stage mesothelioma is affecting one side of the chest, but it has grown into the chest wall’s first layer, or a single place in the chest wall, or the heart’s outer covering layer, or the mediastinum’s fatty part (the mediastinum is the area containing the esophagus, trachea, and thymus).
T4:T4 is the most advanced tumor stage. Mesothelioma has spread from either the right or left pleura lining into the chest wall, muscle, or ribs, or it has spread to the esophagus, trachea, blood vessels, or thymus. It may metastasize to the spine as well. The cancer may affect the opposite side of the chest and can spread through the heart lining and may be affecting the heart itself. The cancer can also spread to the brachial plexus, which are the nerves that control the arm.
Lymph Node Stages
Lymph nodes are clusters of special immune systems cells located under the arms and elsewhere in the body. Cancer frequently involves the lymph nodes. There are three N stages in the TNM system to determine how far the mesothelioma has spread to the lymph nodes.
N0:This means that the cancer has not spread to the lymph nodes.
N1:This means that the cancer cells have spread to lymph nodes on the same side of the chest as the mesothelioma.
N2:At this stage, the cancer has spread into the lymph nodes in front of the heart (the space called the mediastinum) or into the lymph nodes near the left or right bronchi. The cancer-affected lymph nodes are located on the side of the mesothelioma’s origin.
N3:In this stage, the cancer has spread to lymph nodes near the collarbone and/or to lymph nodes on the opposite of the mesothelioma-affected lung.
Metastasis Stages
To determine the stage of mesothelioma, the tumor, lymph node, and metastasis stages are combined (stage grouping).
Stage I (T1, N0, M0): At this stage, mesothelioma has not spread to the lymph nodes or to distant organs. It is localized on one side of the pleural lining and perhaps has spread in a few spots to the lung’s outer lining.
Stage II (T2, N0, M0): At this stage, mesothelioma has spread into the lung’s outer lining or into the diaphragm or inside the lung. There is still no lymph node involvement and the cancer has not spread to distant organs.
Stage III (T 1 or T2, N1 or N2, M0; or T3, N0 or N1 or N2, M0): At this stage the mesothelioma has not metastasized to distant organs, but it has spread considerably in the chest area. It may involve the lung’s interior, the heart’s outer lining, and/or the diaphragm. It may or may not involve the lymph nodes.
Stage IV (T 4, any N, M; or any T, N3, MO; or any T, any N, M 1): In this stage the tumor may be quite advanced and have spread to the opposite side of the chest; the cancer may be inside the lungs, the heart, and/or may be in the mediastinum (the area containing the esophagus, trachea, blood vessels, and thymus). It may have spread to the spine and/or the brachial plexus (the nerves the control the arm). Once pleural mesothelioma is this advanced, it is staged at stage IV, even if there is no lymph node involvement and the cancer has not spread to distant organs.
Pleural mesothelioma may also be designated as stage IV, if there is extensive lymph node involvement (N3) at any T stage, even though the cancer has not metastasized to distant organs.
If pleural mesothelioma has metastasized to distant organs it is also considered stage IV, even if the tumor is localized and there is no lymph node involvement.
The International Mesothelioma Interest Group has developed a staging system for pleural mesothelioma. This system is called the TNM system. It has been adopted by the American Joint Committee on Cancer (AJCC) and it is similar to the staging systems of other forms of cancer.
Pleural mesothelioma is staged by careful examination of imaging studies. TNM stands for the three determining classification stages in the system. ‘T’ designates tumor, ‘N’ denotes the lymph nodes, and ‘M’ represents metastasis (the spread of the cancer to other organs). There are four stages of mesothelioma; each stage is designated by a Roman numeral (I-IV). The information from the TMN classifications combined to determine what stage the cancer has advanced to. Stage I is the earliest stage of mesothelioma; the cancer is localized and has not advanced from its original outbreak site. Stage IV is the end stage of pleural mesothelioma; the cancer has advanced and spread to other organs making it impossible to remove.
Mesothelioma Stages
Within in the TNM system there are four tumor stages (T stages):
T1:Either the right or the left pleura lining (chest lining) is affected by the mesothelioma. The mesothelioma has spread to the lining covering the lung and possibly to a few other minute spots.
T2:At this stage the mesothelioma tumor is affecting one side of the chest, but it has spread into the lung’s outer lining, or the diaphragm, or the lung’s interior.
T3:By this stage mesothelioma is affecting one side of the chest, but it has grown into the chest wall’s first layer, or a single place in the chest wall, or the heart’s outer covering layer, or the mediastinum’s fatty part (the mediastinum is the area containing the esophagus, trachea, and thymus).
T4:T4 is the most advanced tumor stage. Mesothelioma has spread from either the right or left pleura lining into the chest wall, muscle, or ribs, or it has spread to the esophagus, trachea, blood vessels, or thymus. It may metastasize to the spine as well. The cancer may affect the opposite side of the chest and can spread through the heart lining and may be affecting the heart itself. The cancer can also spread to the brachial plexus, which are the nerves that control the arm.
Lymph Node Stages
Lymph nodes are clusters of special immune systems cells located under the arms and elsewhere in the body. Cancer frequently involves the lymph nodes. There are three N stages in the TNM system to determine how far the mesothelioma has spread to the lymph nodes.
N0:This means that the cancer has not spread to the lymph nodes.
N1:This means that the cancer cells have spread to lymph nodes on the same side of the chest as the mesothelioma.
N2:At this stage, the cancer has spread into the lymph nodes in front of the heart (the space called the mediastinum) or into the lymph nodes near the left or right bronchi. The cancer-affected lymph nodes are located on the side of the mesothelioma’s origin.
N3:In this stage, the cancer has spread to lymph nodes near the collarbone and/or to lymph nodes on the opposite of the mesothelioma-affected lung.
Metastasis Stages
To determine the stage of mesothelioma, the tumor, lymph node, and metastasis stages are combined (stage grouping).
Stage I (T1, N0, M0): At this stage, mesothelioma has not spread to the lymph nodes or to distant organs. It is localized on one side of the pleural lining and perhaps has spread in a few spots to the lung’s outer lining.
Stage II (T2, N0, M0): At this stage, mesothelioma has spread into the lung’s outer lining or into the diaphragm or inside the lung. There is still no lymph node involvement and the cancer has not spread to distant organs.
Stage III (T 1 or T2, N1 or N2, M0; or T3, N0 or N1 or N2, M0): At this stage the mesothelioma has not metastasized to distant organs, but it has spread considerably in the chest area. It may involve the lung’s interior, the heart’s outer lining, and/or the diaphragm. It may or may not involve the lymph nodes.
Stage IV (T 4, any N, M; or any T, N3, MO; or any T, any N, M 1): In this stage the tumor may be quite advanced and have spread to the opposite side of the chest; the cancer may be inside the lungs, the heart, and/or may be in the mediastinum (the area containing the esophagus, trachea, blood vessels, and thymus). It may have spread to the spine and/or the brachial plexus (the nerves the control the arm). Once pleural mesothelioma is this advanced, it is staged at stage IV, even if there is no lymph node involvement and the cancer has not spread to distant organs.
Pleural mesothelioma may also be designated as stage IV, if there is extensive lymph node involvement (N3) at any T stage, even though the cancer has not metastasized to distant organs.
If pleural mesothelioma has metastasized to distant organs it is also considered stage IV, even if the tumor is localized and there is no lymph node involvement.