Physicians have developed the Staging System as marker to determine how advanced a given cancer is.  The Staging System applies to all cancers, not just mesothelioma.  The particular stage of a given cancer is usually based on:

• The size of the tumor involved
• How much penetration into bodily tissues it has achieved
• Whether it has spread to the lymph nodes, which lymph nodes, and how many it has invaded
• Whether it has spread to nearby organs / structures (Metastasized)
• Whether it has spread to far away organs / structures (Metastasized)

Physicians / Oncologists stage cancer because it provides an indication of how advanced the cancer is which helps determine the prognosis for the patient, and which treatment modalities may be recommended.

• The most common form of cancer staging is called the TNM Staging System, or Tumor, Node, Metastasis System.  The TNM System contains a clinical stage, and a pathological stage.
• The clinical stage represents the determination of the physician as to the stage of the cancer based on any information which is available before any surgical intervention to remove the tumor or retrieve samples for analysis.
• The pathological stage refines the calculation of the clinical stage, by providing information from a pathological examination of the tumor, whether it be visual microscopic inspection or chemical testing.

Due to the fact that the clinical staging method relies solely on observational elements, and the pathological examination relies on inspection and testing, it is common for there to be two separate staging diagnoses.  The pathological stage estimation is usually preferred, however, as it is based more on testing of the tumor itself rather than mere observation.  This would not be the case, however, if the tumor is not treated surgically, or if the patient undergoes treatment to shrink the tumor before any surgical intervention.  In that case, the pathological estimation may be off.

Generally, the staging estimates will be complimentary and assist the physician in reaching the proper conclusion.  Though there are some other less popular forms of staging, it is unlikely that they will be used to stage a mesothelioma cancer.  While TNM staging is not used for all cancers, and its formula is modified in others, TNM is the preferred method for staging solid mesothelioma tumors.

The TNM results will typically be relayed as part of the “Overall Stage Grouping (OSG).”  The overall stage grouping will be reflected as a Number, 0-IV, which will illustrate the progression of the cancer.  The numbers typically reflect the following progressions:

• Stage 0:  The cancerous cells are tumor are only found “in situ.”  This means the cancer has not spread to any part of the body.
• Stage I:  This stage is reflective of cancers that have only dispersed locally.  Cancerous cells have spread from the original site of the tumor, but have remained localized.
• Stage II:  This stage is reflective of cancers have dispersed only locally, but those local tumors are advanced.
• Stage III:  This stage is similar to Stage II, in that it also reflects local advancement of tumors.  In each cancer, there are typically special qualifications for what constitutes Stage III depending on the level of other tissue involvement.
• Stage IV:  This stage indicates that the cancer has metastasized to other organs and/or throughout the body.

Applying this system, a mesothelioma patient’s physician or oncologist will attempt to stage that cancer, in order to determine the best course of treatment.  This is why it is often important to see a physician as soon as symptoms develop, as the earlier mesothelioma is detected, the more effective treatment is.  Using the above, mesothelioma staging will typically be described as:

• TNM Stage I:  Mesothelioma tumors have been located, whether it be the chest or abdominal cavity.  The tumors may have spread locally, but have not involved the lymph nodes.
• TNM Stage II:  Mesothelioma has become malignant, and has invaded the lymph node on the same side of the body as where the cancer originated.  Additionally, the mesothelioma has metastasized to the lung, pericardial sac, or other immediate structure or organ.
• TNM Stage III:  Mesothelioma has become malignant, and has involved the peritoneum, pericardium, pleura or other organs within the chest on the same side of the body as where the mesothelioma originated.  It has invaded structures different from that in which originated.  It is not necessary to have lymph node involvement.
• TNM Stage IV:  Mesothelioma has become malignant, and has involved the peritoneum, pericardium, pleura or other organs within the chest on the opposite side of the body as where the mesothelioma originated.  It has invaded structures different from that in which in originated.

Prior to the development of the TNM System, oncologists and physicians used the Butchart System to stage mesothelioma.  The Butchart System calculates the stage of the cancer by focusing on the mass or size of the cancerous tumor.  Using the Butchart System, mesothelioma would be staged in the following ways:

• Butchart Stage I:  Mesothelioma is present on either side of the chest cavity.
• Butchart Stage II: Mesothelioma is present in the pleura on BOTH sides of the body.  Mesothelioma may also be present in other organs in the chest, or in the lymph nodes.
• Butchart Stage III:  Mesothelioma is present in the abdominal cavity.  It may also be found in other structures or lymph nodes outside the chest / abdominal cavity.
• Butchart Stage IV:  Mesothelioma is present in other bodily organs.  Mesothelioma is also present in the blood stream.

A final system which is used by oncologists and physicians in diagnosing Mesothelioma involvement is the Brigham System.  The Brigham System is geared toward surgical intervention, however, and is not based on the involvement of other organs or lymph nodes except in determining whether surgery is appropriate based on location.  The Brigham system stages Mesothelioma as follows:

• Brigham Stage I:  Mesothelioma is localized and has not affected the lymph nodes.  The mesothelioma tumor is still resectable at this point.
• Brigham Stage II:  Mesothelioma has spread to the lymph nodes, but the tumor is still resectable.
• Brigham Stage III:  Mesothelioma has spread and invaded the chest wall, heart, esophagus, or other chest organs, or the abdominal cavity.  It may or may not have spread into the lymph nodes.  Mesothelioma tumor is not resectable at this Stage.
• Brigham Stage IV:  Mesothelioma has not only invaded local organs and structures, but has invaded far removed organs and entered the blood stream.  Mesothelioma is not resectable at this point.

• The unfortunate aspect about Mesothelioma is that due to the long latency period, where an individual has no symptoms (asymptomatic), the individual may have no knowledge that a tumor has formed until it begins to cause physical limitations or suffering.  At this point, it can be too late as the prognosis for mesothelioma gets progressively worse the longer it is untreated.

• Many Veterans hospitals now place high-risk individuals on screening programs, in the hopes of early detection.  Basically, this means that if a patient worked in a high-risk field in the military for asbestos exposure, such as the Navy or Air Force, that patient will receive yearly or bi-yearly screenings to check for pleural thickenings, effusions, or any possible sign that mesothelioma may develop.  This will hopefully lead to early diagnosis and assist in treatment.