How is Mesothelioma Staged?
When an individual is diagnosed with pleural mesothelioma, it is important to know what stage the cancer has progressed to as early diagnosis generally results in a more favorable prognosis. In order to find out how far the cancer has spread and what treatment options may be available, doctors will commonly use a staging system.
There are three primary staging systems that doctors use today. While each system varies slightly in terms of what is specifically being measured each one uses four stages to classify how far the disease has progressed.
Butchart Staging System
The Butchart system is the most common staging system used by doctors to diagnose mesothelioma patients. This system measures the extent of the primary tumor, and classifies the mesothelioma into one of four stages.
In Stage I, mesothelioma exists in either the right or left pleura. The lung, pericardium, or diaphragm on the same side may also be involved.
In Stage II, mesothelioma may be present in the heart or both sides of the pleura and iinvades the chest wall or involves the esophagus. Lymph node involvement in the chest may also be present.
In Stage III, additional lymph nodes beyond the chest may be involved and the mesothelioma has penetrated moved through the diaphragm and invaded the peritoneum.
In Stage IV, the cancer has metastasized to other organs and the bloodstream.
TNM Staging System
The TNM Staging System recently developed by the American Joint Committee on Cancer, is similar to the other staging systems. T stands for tumor and evaluates size and whether or not it is localized. N stands for Node and evaluates lymph node involvement. M stands for Metastasis and measures progression of the disease throughout the body.
As in the Butchart System, the mesothelioma is in either the right or left pleura. There is no sign of lymph node involvement but there may be indications of movement into the lining of the lung, pericardium or diaphragm.
Mesothelioma may have spread into the lung, pericardium, or diaphragm on the same side, and may involve the lymph nodes on that same side.
Mesothelioma has progressed into the chest wall muscle or other organs in the chest on the same side and may also have spread to the lymph nodes.
Mesothelioma has spread into the lymph nodes on the opposite side of the chest. It may also involve the pleura or lung on the opposite side, or have entered the peritoneum, or abdominal organs. In this stage there is also evidence of distant metastases to other organs.
Brigham Staging System
The Brigham Staging System defines whether or not surgery is a viable treatment option for a mesothelioma patient and whether or not there is lymph node involvement. It is similar to both the Butchart Staging System and the TNM Staging System in that it defines the progression of mesothelioma in four stages.
The Brigham Staging System helps doctors determine what types of treatment options are available to a mesothelioma patient and like the previous two systems, uses a four tier classification system.
Surgery is still a possible treatment option in Stage II as the mesothelioma remains localized. Lymph node involvement is detected.
Surgical intervention is no longer an option. The mesothelioma has spread into the chest wall, heart, or through the diaphragm into the peritoneum. Lymph node involvement may or may not be present.
When diagnosed in Stage IV, a patient's prognosis is the least favorable. Mesothelioma has metastasized to other organs and the cancer is pervasive in the body
These staging systems provide doctors with information that allows them to accurately determine a patient's prognosis and assess therapeutic treatment options.