How is mesothelioma staged?
Mesothelioma stages are the assessment levels that doctors use to determine the extent of the cancer within the body. Upon being diagnosed, the mesothelioma cancer will be given a stage between 1 and 4, with Stage 4 mesothelioma being the most severe.
As with the staging of other types of cancer, the stage is determined only at diagnosis and does not change. For example, if a Stage 1 mesothelioma tumor spreads to other parts of the body, it is still called Stage 1 with metastasis; likewise, if a later stage mesothelioma tumor reduces in size or goes into remission, the stage will not change. Of course, treatment may change depending on the patient’s individual circumstances.
Given the rarity of mesothelioma, a formal staging classification exists only for pleural mesothelioma – the most common variety – which affects the lining of the lung and chest cavity. Basic staging can be determined through the use of imaging scans, which provide cancer specialists with a visual representation of the extent of the tumor within the body. If the results of imaging scans are inconclusive or it appears that the disease is not localized, a physician may ask the patient to undergo biopsy to determine whether the malignant cells have metastasized to the blood or lymph nodes through laboratory testing.
The Stages of Mesothelioma
The four stages of mesothelioma, as noted above, vary slightly within each system but can be generally characterized as indicated below. Please click into the individual pages to get more information about each stage in general and as it is defined within each staging system:
In Stage 1 the tumor is localized, there is no lymph node involvement, and the cancer has not spread to other organs or tissues. In this case, the cancer is likely restricted to one side of the pleura and surgical removal is typically feasible.
In Stage 2, the tumor is larger and has invaded the lung or diaphragm. Lymph nodes may also be involved. In this case, surgical resection may be possible though the cancer has likely spread to both sides of the pleura.
In Stage 3, mesothelioma has invaded a single region or area such as the chest wall, esophagus, and/or lymph nodes, and surgical resection is generally ruled out as a potential beneficial treatment.
In Stage 4, mesothelioma has invaded multiple regions such as different areas of the chest wall, the diaphragm and/or the pericardium. Lymph nodes are also involved and the cancer has spread to other organs. Surgical removal provides no value in this case as the disease has likely metastasized well beyond its origin.
Pleural Mesothelioma Staging Systems
Three different systems are used to determine the stage of mesothelioma. Each system contains four stages, the definitions of which vary slightly. Learn more about each staging system for mesothelioma by selecting the appropriate link below.
Note that mesothelioma-specific staging systems only exist for pleural mesothelioma. Rarer forms of mesothelioma do not have their own staging systems.
The Butchart staging system is the oldest and most commonly utilized staging system for mesothelioma. This system is focused on defining the location of the primary tumor mass in the body for each stage. The system doesn’t address how many cancer cells are present, how big the tumor is or the level of cancer present in the body overall.
The TNM Staging System, developed by the American Joint Committee on Cancer (AJCC), is a staging system used for many different types of cancer. The current version of the TNM Staging System is detailed in the AJCC Cancer Staging Manual (7th ed., 2009). It considers the characteristics of the tumor (T), involvement of the lymph nodes (N), and whether the cancer has metastasized (M) to other locations within the body.
The Brigham Staging System also has four stages of progression. The primary difference of the Brigham System from the others is that, in addition to identifying tumor characteristics and spreading to lymph nodes or other parts of the body, the Brigham System assesses the efficacy of surgical intervention at each stage.
Staging for Peritoneal and Pericardial Mesothelioma
Due to the rarity of these forms of an already rare disease, no staging systems have been designed specifically for these types of mesothelioma.
That said, the American Joint Committee on Cancer (AJCC) has published general guidelines for staging cancer in its AJCC Cancer Staging Manual. Therefore, even when doctors do not have guidelines for a specific form of cancer, they can still refer to the general guidelines to help determine the stages of extremely rare cancers like peritoneal mesothelioma and pericardial mesothelioma.
Butchart EG, Ashcroft T, Barnsley WC, Holden MP. Pleuropneumonectomy in the management of diffuse malignant mesothelioma of the pleura: experience with 29 patients. Thorax. 1976;31:15-24.
Edge S, Byrd DR, Compton CC, Fritz AG, Greene FL, Trotti A, ed. AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer-Verlag;2010.
Flores RM, Rush VW. Staging of Mesothelioma. In: Pass HI, Vogelzang N, Carbone M, ed. Malignant Mesothelioma: Pathogenesis, Diagnosis, and Translational Therapies. New York, NY: Springer;2005:402-415.
Sugarbaker DJ, et al. Resection margins, extrapleural nodal status, and cell type determine postoperative long-term survival in trimodality therapy of malignant pleural mesothelioma: results in 183 patients. J Thorac Cardiovasc Surg. 1999 Jan;117(1):54-63; discussion 63-5.