For several decades, oncologists have diagnosed cancer and monitored its progress in terms of "stages." Staging allows doctors to determine to what extent an individual's cancer has developed and whether or not it has spread and to where. Also, the proper staging of cancer allows the oncologist to determine the best course of mesothelioma treatment for the patient.
Pleural mesothelioma, the most common form of the disease, is staged in the same manner as most cancers though a staging system is not yet in place for peritoneal and pericardial mesothelioma, the rarer forms of this aggressive cancer.
Currently, the three systems that are used to stage this disease are the Butchart, TNM, and Brigham systems. Each is a bit different and which is used may depend on the physician in charge or the facility at which the patient is being treated.
The Butchart System
Butchart is the oldest system in place and is still the most commonly used. This system is based on the extent of primary tumor mass.
- Stage I: Mesothelioma is present in the right or left pleura (the thin, transparent membrane which covers the lungs and lines the inside of the chest walls) and may also involve the diaphragm (the muscle separating the chest from the abdomen) on the same side.
- Stage II: Mesothelioma has invaded the chest wall or involves the esophagus (food passage connecting the throat to the stomach, heart, or pleura on both sides. Lymph nodes in the chest may also be involved once the cancer reaches Stage II.
- Stage III: Mesothelioma has penetrated through the diaphragm into the lining of the abdominal cavity or peritoneum. Lymph nodes beyond those in the chest may also be affected.
- Stage IV: There is evidence of metastasis (the spreading of the mesothelioma) through the bloodstream to other organs.
This system considers three components; the first letter of each forming the name of the system. Doctors using TNM will look at the tumor, lymph nodes, and whether the cancer has metastasized. Like the Butchart system, it is divided into four stages.
- Stage I: Mesothelioma involves right or left pleura and may also have spread to the lung, pericardium (the fluid filled sac that surrounds the heart), or diaphragm on the same side. Lymph nodes are not yet involved.
- Stage II: Mesothelioma has now 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 has now invaded the chest wall, muscle, ribs, heart, esophagus, or other organs in the chest on the same side. It may or may not have 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 metastasis is included in this stage.
The system used least for the diagnosis and staging of mesothelioma is the Brigham System. It addresses the ability to surgically remove the tumor (resectability) and the involvement of the lymph nodes. (Because mesothelioma is often diagnosed in its later stages, surgery is often not an option.) Its stages include:
- Stage I: At this point, mesothelioma is resectable and there is no lymph node involvement.
- Stage II: Mesothelioma is still respectable during stage II, but the lymph nodes are now involved.
- Stage III: This stage involves the presence of unresectable mesothelioma extending into the chest wall, heart, or through the diaphragm or peritoneum; with or without extra-thoracic lymph node involvement.
- Stage IV: This stage indicates distant metastatic disease (widespread cancer throughout the body).
- Cancer Help, UK: The Stages of Mesothelioma. http://www.cancerhelp.org.uk/help/default.asp?page=4465
- National Cancer Institute: Stages of Mesothelioma http://www.cancer.gov/cancertopics/pdq/treatment/malignantmesothelioma/Patient/page2
- American Cancer Society: How is Malignant Mesothelioma Staged http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_malignant_mesothelioma_staged_29.asp?sitearea=
Last modified: February 15, 2010.