Mesothelioma Cancer Staging Systems
Physicians use a standardized staging system to better diagnose a mesothelioma patient, assess the growth of the disease and determine the best treatment options.
Depending on the spread of the disease, doctors use a variety of techniques to treat the disease or offer palliative care. The three main staging systems are TNM, Butchart and Brigham. Although all three systems are primarily aimed at pleural mesothelioma because it is the most common, the stages also apply to the less common peritoneal and pericardial types.
TNM Staging System
Of the three staging systems, TNM, which stands for tumor, lymph nodes and metastasis, is the most detailed and complex. It assesses the disease according to a variety of factors. This staging system was developed by the American Joint Committee on Cancer and is widely accepted as a universal staging system in all types of cancer. In 1995, the International Mesothelioma Interest Group (IMIG) adapted the TNM system for mesothelioma to standardize a diagnosis.
Each component of the TNM system is further broken down into subcategories to allow for a detailed diagnosis. For example, in diagnosis the T, or tumor involvement, the disease ranges in severity from TX, which indicates there is no primary tumor, to T4, which confirms the presence of advanced tumors. The same type of staging range is applied to N, or lymph nodes, and the overall growth or metastasis (M) of the disease.
From this, the disease is staged from less severe (stage I) to severe (stage IV):
- Stage I -- The cancer is localized to the mesothelium, or the membrane that covers the chest wall. It also may be localized to the lungs or diaphragm. At this stage, surgical removal of the cancer is typically an option. Chemotherapy may also be used.
- Stage II – The cancer has moved into the lungs and/or the diaphragm but has not spread to distant locations.
- Stage III – The mesothelioma has spread into the chest wall, heart, ribs and other organs on the same side as the main tumor. It has also spread to some local lymph nodes.
- Stage IV – The mesothelioma has spread to the opposite side of the primary tumor, into the lungs and into outer lying lymph nodes.
Butchart Staging System
This staging system is the oldest among the three, developed in 1976 by Dr. Eric Butchart. It is known to be simple and useful for choosing the best treatment and diagnostic options and is the most commonly used staging system used in all types of cancer. Butchart established the system to identify patients who are the best candidate for radical cancer treatments. This system defines the tumor location but is not as precise and detailed as the TNM system. In many cases, mesothelioma patients in Butchart stage I or II are typically candidates for curative treatments, while those in the later stages are candidates for palliative treatments.
Like the TNM system, the Butchart system utilizes stages that describe the severity of the disease process:
- Stage I – The cancer tumor is confined to one side of the localized area, including a lung, one side of the pericardium or the diaphragm.
- Stage II – The mesothelioma has invaded the esophagus, the chest wall, heart and both sides of the pleura. Chest lymph nodes may also be involved.
- Stage III – The mesothelioma has spread into the lining of the chest cavity, called the peritoneum, and distant lymph nodes.
- Stage IV – The cancer has spread into the blood stream and other distant organs.
Brigham Staging System
Created by renowned thoracic surgeon and mesothelioma specialist Dr. David Sugarbaker at the Brigham and Women’s Hospital at Harvard, this system is based on details of the tumors and if the patient is a candidate for mesothelioma surgery ( link to Meso surgery page):
- Stage I – The cancer is confined to one side of the pericardium. Curative surgery is an option.
- Stage II – Tumors have spread through the chest walls. The cancer cells have also spread to lymph nodes in the chest area. High-dose radiation is the recommended treatment.
- Stage III –Tumors have penetrated the peritoneum or the diaphragm, and the cancerous cells have traveled to distant lymph nodes. In this stage, there are typically no curative treatments.
- Stage IV – The tumors have spread inside the body. Only palliative treatments are available.