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MESOTHELIOMA STAGES
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| Healthy
Lung |
Onset of
Disease |
Mesothelioma Infected |
How Is Malignant Mesothelioma
Staged?
Staging is the process of finding out how
far the cancer has spread. Staging of mesothelioma is based on imaging
studies such as x-rays, CT scans, and MRI scans. The treatment and outlook
for patients with mesothelioma largely depends on the stage (extent of
spread) of their cancer. Since pleural mesothelioma occurs most frequently
and has been studied the most, it is the only mesothelioma for which a
staging classification exists.
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.
Stage I
Mesothelioma is present on one side of the
chest only and isn’t growing into the chest wall.
Stage II
Mesothelioma invades the chest wall or
involves the esophagus (food passage connecting the throat to the
stomach), heart, or has grown into the pleura on the other side of the
chest.. The lymph nodes in the chest may also be involved.
Stage III
Mesothelioma has grown through the
diaphragm into the peritoneum (lining of the abdominal cavity) or
has spread to lymph nodes beyond those in the chest.
Stage IV
Mesothelioma has spread through the
bloodstream to other organs (metastases).
Another staging system has recently been
developed by the International Mesothelioma Interest Group and adopted by
the American Joint Committee on Cancer (AJCC). This is a TNM
system, similar to staging systems used for most other cancers. T
stands for tumor (its size and how far it has spread to nearby
organs), N stands for spread to lymph nodes and
M is for metastasis (spread to distant organs). In
TNM staging, information about the tumor, lymph nodes, and metastasis is
combined in a process called stage grouping to assign a stage described by
Roman numerals from I to IV. Major cancer centers are beginning to use
this system instead of the Butchart staging because it more accurately
depicts the extent of tumor.
Stage I
Mesothelioma involves either the right or
left pleura lining the chest. It has only spread to the outer lining of
the lung in, at most, a few small spots. It has not yet spread to the
lymph nodes.
Stage II
Mesothelioma involves either the right or
left pleura lining the chest and has spread from the lining of the chest
into 1) the outer lining of the lung or 2) the diaphragm or 3) into the
lung itself.
Stage III
Mesothelioma involves either the right or
left pleura lining the chest and has spread into 1) the first layer of the
chest wall, or 2) the fatty part of the mediastinum, or 3) a single place
in the chest wall or 4) the outer covering layer of the heart or 5) lymph
nodes anywhere in the same side of the chest.
Stage IV
Mesothelioma involves either the right or
left pleura lining the chest and has spread 1) into the chest wall, either
muscle or ribs, or 2) through the diaphragm, or 3) into any organ
contained in the mediastinum (esophagus, trachea, thymus, blood vessels),
or 4) into the spine, or 5) across to the pleura on the other side of the
chest, or 6) through the heart lining or into the heart itself, or 7) into
the brachial plexus (nerves leading to the arm), or 8) into lymph nodes
outside that side of the chest, or 9) spread to other organs through the
bloodstream.
Experts recommend that this staging system
should be used instead of the original Butchart staging system.
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