If Mesothelioma is diagnosed, the doctor needs to know the stage
, or extent, of the disease to plan the best treatment. Staging is a careful attempt to find out whether the cancer has spread. Also, the doctor will perform more tests to identify if the cancer has spread to other areas of the body. Such tests may include imaging tests -- CT scan, magnetic resonance imaging (MRI), bone scan, or x-ray.
The first section on this page explains how cancer spreads. The second section provides an overview of the additional tests that will likely be performed once Mesothelioma is diagnosed. The third section explains the staging of Mesothelioma itself.
The Spreading of Cancer
There are three ways that cancer spreads in the body:
Cancer invades the surrounding normal tissue.
Through the lymph system.
Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
Through the blood.
Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary tumor and travel through the lymph or blood to other places in the body, another, or secondary tumor, may form. This process is called metastasis
. The secondary, or metastatic, tumor is the same type of cancer as the primary tumor. For example, if Mesothelioma spreads to the bones, the cancer cells in the bones are actually Mesothelioma cancer cells. The disease is Metastatic Mesothelioma
, not bone cancer.
Once Mesothelioma has been diagnosed, another series of tests will be run to establish if and where the cancer has spread. Following are the most common tests:
CT Scan (CAT Scan):
A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. A CT scan of the chest and abdomen may be used to check for primary small cell lung cancer, or to find Merkel cell carcinoma that has spread. A CT scan of the head and neck may also be used to find Merkel cell carcinoma that has spread to the lymph nodes. This procedure is also called computed tomography
, computerized tomography
, or computerized axial tomography
MRI (Magnetic Resonance Imaging):
A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called Nuclear Magnetic Resonance Imaging (NMRI).
An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
Endoscopic Ultrasound (EUS):
A procedure in which an endoscpe
is inserted into the body. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography
. This test may be used to guide fine-needle aspiration (FNA) of the lung, lymph nodes or other areas.
Stages of Mesothelioma
The stages of malignant mesothelioma are divided into two groups. Malignant Mesothelioma stages are grouped into localized and advanced.
Localized Malignant Mesothelioma (stage I)
In Localized Malignant Mesothelioma stage I, cancer is found in the lining of the chest wall and may also be found in the lining of the lung, the lining of the diaphragm or the lining of the sac that covers the heart on the same side of the chest.
Advanced Malignant Mesothelioma (stage II, stage III, and stage IV)
In stage II,
cancer is found in the lining of the chest wall and the lymph nodes on the same side of the chest. Cancer may also be found iin the lining of the lung, the lining of the diaphragm or the lining of the sac that covers the heart on the same side of the chest.
In stage III
, cancer has spread to the chest wall, the mediastinum, the heart, beyond the diaphragm and the peritoneum. Cancer may have also spread to the lymph nodes on the other side of the chest or outside of the chest.
In stage IV
, cancer has spread to distant organs and tissues.