Staging of Mesothelioma

The only type of mesothelioma that can be formally staged is malignant pleural mesothelioma (MPM). The method for formally staging malignant pleural mesothelioma is known as the TNM staging system. This system is used by the American Joint Committee on Cancer (AJCC) for staging mesothelioma.

As our Boston mesothelioma lawyers have seen various cases, mesothelioma can also form in the chest cavity where it is known as malignant pericardial mesothelioma, or the abdomen where it known as malignant peritoneal mesothelioma.

While these types of mesothelioma can’t be classified using the TNM System, it should be noted that malignant pleural mesothelioma is the most common type of mesothelioma and exposure to asbestos is the only known cause.

How is Mesothelioma Staged?

Using the TMN staging system, the tumor (T) grown is classified, as it is spread to nearby lymph nodes (N) and whether it has metastasized (M) in other parts of the human body. This is what the acronym TNM stands for in the context of malignant pleural mesothelioma tumors.

Once the T,N, and M values have been established, the groups of three will be further classified into stages I through IV, with I being the least advanced mesothelioma and stage IV mesothelioma being the most advanced.

When people talk about “end stage” cancer, they are talking about stage IV mesothelioma as this is the most advanced stage of the disease and, there are few remaining treatment options. Even surgery is usually not an option at this stage in a mesothelioma case.

What is TNM Staging?

Before we can discuss the different stages of malignant pleural mesothelioma (stages I though IV), it will be helpful to discuss how the TNM system work, because that is the system on which mesothelioma staging is based.

As discussed by the U.S. Centers for Disease Control (CDC), the TNM system was created by the American Joint Committee on Cancer. The data collected form CDC surveillance studies is collected and entered into a database created by the CDC to power a software program that can be used to help oncologists stage malignant pleural mesothelioma in a uniform manner.

While malignant pleural mesothelioma is the only type of mesothelioma that can be staged using the TNM system, the system itself can be used to stage other types of cancer such as the following:

  • Breast
  • Lung
  • Lymphoma
  • Malignant Mesothelioma of the Iris

Once the values for each individual part of this TNM classification model are known, the software program will take the codes and do the work of giving the cancer a stage assignment.

The first thing that must be done is to determine the size of the main tumor. This is done by measuring it with imaging equipment and assigning it a value from T1 to T4. If the main tumor can’t be located for some reason, it will be assigned a value of TX. This doesn’t mean there isn’t a main tumor, but it means that there is no positive identification. In cases where there is evidence of a main tumor based upon other tests, but it can’t be properly measured, doctors will give it a value of T0. Again, this like a TX classification doesn’t mean a main tumor doesn’t exist.

The next thing that must be established is whether the main cancer has spread to the surrounding lymph nodes. As discussed by WebMD, lymph nodes are a very important part of the human body’s immune system. They are used to filter fluid known as lymph fluid. When the lymph fluid flows though the lymph system, bacteria, foreign bodies, and viruses suspended in the fluid will become trapped and removed. Lymph nodes contain a specialized type of cell called lymphocytes that will destroy these harmful elements in fluid. They are located throughout the body including around the lungs.

As our Boston mesothelioma lawyers at Jeffrey Glassman Injury Lawyers have seen in many cases over the years, the main tumor will often spread to these lymph nodes. This spread of cancer to these lymph nodes is measured using the N scale ranging from NX to N4, as it is done with the T group for main tumor size.

Finally, the oncologist must assess whether the tumor has metastasized (spread) to other parts of the victim’s body. As discussed above, malignant pleural mesothelioma will form in the lungs but can quickly spread to other parts of the body.

Once an oncologist knows the values for T, N, and M, they will look at the actual combination for the case at hand and then the doctor, or a computer program will be able to stage the malignant mesothelioma.

For example, victim may have a TNM value of T1, N0, M0. This means that the tumor is in the pleural lining of the chest wall on one side of the patient’s chest. This means that the cancer is not bilateral at this point. The N value means that there is no evidence the tumor has spread to the nearby lymph nodes, and the M value means that it has not metastasized in other parts of the victim’s body.

At this point, we can enter the code combination T1, N0, M0 into the mesothelioma staging model, and we can see that the cancer is in Stage I. If the patient had a TNM value of T2, N0, M0, for example, that would mean that the tumor has grown into the pleural lining of the chest wall on one side of the victim’s chest, and it would also mean that the tumor has reached the diaphragm and the mediastinum. This is more advanced stage of cancer, but there is still no evidence that it has spread to the lymph nodes or metastasized in other parts of the body. At this point, the malignant pleural mesothelioma would be considered Stage II cancer.

A rating of T1 or T2, N1 or N2, with an M rating of M0 would be considered Stage III malignant mesothelioma. This is often very advanced, but is not the most advanced stage of malignant mesothelioma. At this stage, it may still be possible to remove the tumor through a process oncologists refer to as resection. Stage IV is the most serious form of malignant pleural mesothelioma and is generally considered unresectable.

If you have been diagnosed with mesothelioma, you may have a viable claim for damages. We can help.

Contact Jeffrey Glassman Injury Lawyers today for a free and confidential consultation.


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