Like other types of cancer, mesothelioma is grouped according to stage. This involves assessing the cancer to see how big it is, how localized it is, and whether or not the cancer has invaded other tissues of the body, such as the bone or bloodstream. People with a less advanced stage of cancer tend to do better, live longer, and have a better chance of remission than those with advanced stages of mesothelioma.
How Mesothelioma is Staged
There are several staging methods used in assessing and treating mesothelioma. There are also different staging criteria depending on where the mesothelioma is located (in the lungs versus the abdomen).
Stages of pleural mesothelioma include the following stages. Keep in mind that the further away from the origin of the cancer, the higher the stage. Staging helps doctors know which treatments are better for you. Research into staging and treatment help doctors understand which treatments work the best for the different stages of mesothelioma.
- Stage 1 Pleural Mesothelioma. This is further subdivided into stage 1A and stage 1B. Stage 1A disease means that only the parietal or outer layer of the pleura is involved while stage 1B means that only the inner or “visceral” layer of the pleura has become affected by cancer. People with stage 1 disease have the greatest potential for a definitive cure. In stage 1 disease, the cancer is located on only one side of the body and is located to one or both of the linings in a specific area of the chest cavity. The lining of the diaphragm can be involved in stage 1 pleural disease.
- Stage 2 Pleural Mesothelioma. In stage 2 disease, there has been spread of the cancer to other areas of the lung or the lining of the lungs. The cancer is still just on one side of the chest cavity but it has spread within that space. Treatment generally involves surgical intervention to remove all visible signs of cancer from the areas where it has been located. A common type of surgery used in stage 2 disease is called an extrapleural pneumonectomy or just a pleurectomy. In stage 2 disease, metastasis has occurred on parts of the diaphragm, the nearby lymph nodes or into surrounding lung tissue. The chances of survival are lower with stage 2 disease because there is always the chance that surgery did not remove all of the disease and it comes back.
- Stage 3 Pleural Mesothelioma. In this stage, still only one side of the chest is affected by the cancer but doctors can identify lymph node involvement with cancerous tissue. Nearby organ spread is possible so that surgery may do nothing to cure the disease. Common areas of spread in stage 3 pleural mesothelioma include spread to the muscle and cartilaginous tissue between the ribs and the chest wall lining, the pericardial sac, or to fatty areas between the lobes of the lungs.
- Stage 4 Pleural Mesothelioma. This is the most advanced stage of mesothelioma. Severe symptoms such as the constant coughing up of blood or difficulty swallowing are not uncommon. There is generally no cure for stage 4 pleural mesothelioma and treatment is mainly designed around keeping you comfortable. Chemotherapy and radiation are often used to shrink as much of the cancer as possible even though a cure is unlikely. Cancer cells can be found on the opposite side of the chest where the original cancer began, on the diaphragm, within the lymph system and on the peritoneum. Even bony metastases of the spine or distant body areas are possible in this late stage of cancer.
Staging of Peritoneal Mesothelioma
There is no single way of staging peritoneal mesothelioma. Most doctors simply describe this type of cancer as “localized” in one area of the abdomen or “metastasized” to other body areas. The abdomen is more complicated than the chest cavity so the lymph nodes, fatty tissue, peritoneum, and organ systems can be involved with cancer.