At diagnosis of mesothelioma, your physician may assess your cancer in a process called staging, as guided by the standards of the Internal Mesothelioma Interest Group (IMIG) Staging System. This assessment is used to gain more insight into the location(s) and severity of your mesothelioma diagnosis. There are 4 stages of mesothelioma, as defined by the IMIG Staging System. The 4 stages both define how far the mesothelioma has spread and help physicians determine the best course of treatment as well as prognosis. These stages are determined based on the imaging tests and biopsies used to diagnose mesothelioma.
Pleural Mesothelioma
Stage 1
Stage 1 is the earliest stage in the mesothelioma stage classification and often renders the most positive prognosis of all the stages, with the most treatment options available. In Stage 1 mesothelioma, the cancer is localized on one side of the chest, has not deviated from its origin, and can be found in any of the following:
- Lining of chest wall
- Lining between chest wall and lungs
- Lining of diaphragm
Stage 2
Stage 2 refers to mesothelioma that is considered to be in an advanced stage, as it has begun to metastasize (spread) to other locales along the chest wall and lungs. Someone who has been diagnosed with stage 2 mesothelioma has a cancer that encompasses the qualities of stage 1 mesothelioma, but that has spread to:
- Surrounding lung tissue
- Areas of the diaphragm
- Areas of the lymphatic system
Stage 3
Stage 3 mesothelioma cancer has spread into the chest wall, diaphragm, stomach or heart. By the time mesothelioma cancer is diagnosed as stage 3, it has already or has potential to spread into other areas of the body including:
- Tissues between ribs and chest cavity wall
- Between the lungs (in the mediastinal fat)
- Within the chest wall
- The pericardial sac
- The lining of the diaphragm and within the diaphragm itself
- The lining of the lung and within the lung itself
- The lining of the chest cavity between the lungs
Stage 4
Stage 4 mesothelioma cancer has spread to the opposite side of the chest and has substantially metastasized to other organs and tissues throughout the body. This is considered the latest stage classification. In this stage, mesothelioma frequently spreads to other areas of the body, such as:
- The lymphatic system and blood vessels
- The opposite side of the chest that it originated in, as well as the diaphragm and peritoneum
- The spine
- All organs within the chest cavity
- Other distant organs, such as the brain, thyroid, or prostate in men
Once the stage of mesothelioma has been determined, your individual diagnosis will be further specified by a combination of letters and numbers according to the TNM system. The TNM Staging System for pleural mesothelioma uses the size and location of the tumor (T), involvement of the lymph nodes (N), and whether the cancer has spread to other parts of the body, or metastasized (M) to determine stages.
If mesothelioma is diagnosed, it is important to begin treatment as soon as possible. CLICK HERE to request a FREE mesothelioma book written by medical professionals and learn more about mesothelioma.