Mesothelioma Stages


Mesothelioma is a degenerative condition, meaning it gets progressively worse as the cancer advances. At diagnosis, doctors stage the patient’s condition, which helps them develop the most effective treatment plan based on how far the mesothelioma has spread.

Mesothelioma Stages Overview

If you’ve been diagnosed with mesothelioma, it’s important to seek the second opinion of a mesothelioma specialist who can determine your stage. Having a correct stage diagnosis is vital to receiving the most effective treatments.

Here’s what you need to know about how doctors stage mesothelioma:

  • Pleural mesothelioma is staged 1-4 from most localized to most metastasized
  • Peritoneal and pericardial mesothelioma do not have official stages, and doctors instead determine stage by early vs. advanced
  • Doctors use three different staging systems to determine how mesothelioma has advanced
  • Treatments are available no matter what stage a patient is diagnosed at
  • Early-stage treatments involve aggressive surgeries and late-stage treatments involve palliative care
  • All patients should seek a second opinion from a mesothelioma specialist on their disease stage

Mesothelioma Staging Systems

Doctors use 3 different staging systems to stage mesothelioma. Each system has its own set of criteria that allows doctors to diagnose a mesothelioma patient by stage. In general, all the stages are concerned with the level of metastasis in patients, as this is ultimately what determines the types of treatments patients can undergo.

The three staging systems doctors use for mesothelioma are:

  • TMN System: Doctors look at the mesothelioma tumor (T) size, shape, and location as well as the level of metastasis (M) and lymph node (N) involvement.
  • Brigham System: Developed by the late Dr. David Sugarbaker—a former leading pleural mesothelioma specialist—while at Brigham & Women’s Hospital, the Brigham system determines whether or not a patient is a good candidate for resectable surgery. According to the Brigham system, stage 1 and 2 patients can undergo curative surgery, while stage 3 and 4 patients cannot.
  • Butchart System: The first mesothelioma staging system, the Butchart system is concerned with the main mesothelioma tumor location as opposed to its size and how many cells have spread.

Depending on the specialist you see, doctors may blend criteria from these 3 systems together to give you their expert opinion on your disease stage.

Additionally, some doctors may use these staging systems to help diagnose peritoneal mesothelioma, which doesn’t have an official staging system yet.

To determine the stage, doctors look at the patient’s condition and assess different factors about how the disease has progressed at diagnosis. With these factors, doctors can classify the condition based on the corresponding criteria of each stage.

Some of the factors that doctors look at when staging mesothelioma include:

  • Tumor size and shape
  • Location of the primary tumor (the point where the tumor first developed)
  • How distantly the mesothelioma has spread from the primary location
  • Whether lymph nodes are involved in the metastasis
  • Whether the mesothelioma can be resected (removed surgically)

Pleural Mesothelioma Stages

As the most common form of mesothelioma, pleural mesothelioma is the only form of this disease that has been given an official staging system. Pleural mesothelioma has 2 important surgical treatments that can effectively remove mesothelioma if detected early enough—the extrapleural pneumonectomy and the pleurectomy with decortication.

Accurate staging of pleural mesothelioma is vital in determining whether or not a patient can undergo surgery to remove the mesothelioma.

Here are the 4 general stages of pleural mesothelioma based on the three staging systems used:

Stage 1

1A: Tumor is contained in one layer of the pleura, which is its primary location.

1B: Tumor is growing in both the parietal (outer) and visceral (inner) layers of the pleura.

Stage 2

The tumor has metastasized slightly to lung tissues or to the chest wall. There is possible lymph node involvement in stage 2, but the tumor has not yet spread to the other side of the chest.

Stage 3

Mesothelioma has metastasized to distant sites such as the deep tissues in the rib cage, the pericardium (heart lining) and/or the tissues in the chest wall beyond the pleura. Stage 3 also has lymph node involvement.

Stage 4

The final and most advanced stage, the fourth stage of mesothelioma involves metastasis to the other side of the chest or to nearby organs such as the heart or diaphragm. Because of lymph node involvement, mesothelioma can also spread to distant sites such as the brain or liver.

Mesothelioma Justice Network Brief

Most patients are diagnosed at stage 3 pleural mesothelioma, and very few are ever diagnosed as early as stage 1 or 2.


Peritoneal Mesothelioma Stages

Though peritoneal mesothelioma is the second most common form of this disease, it doesn’t yet have an established or universal staging systems doctors can use at diagnosis. Without enough past cases to identify consistent criteria, doctors cannot properly stage peritoneal mesothelioma.

Peritoneal mesothelioma specialists categorize the level of metastasis either as early or late. Early peritoneal mesothelioma generally means that the primary tumor remains contained to the peritoneal cavity, while late-stage means that the tumor has spread outside.

Some specialists also go so far as to stage peritoneal mesothelioma with the following four categories:

  • Category 1: Tumors are localized and fully resectable.
  • Category 2: Tumors are contained to the peritoneal organ surfaces and can only be debulked (removed but not fully).
  • Category 3: Tumors remain in the peritoneal cavity but have spread into organs.
  • Category 4: Tumors have spread beyond the peritoneal cavity and there is lymph node involvement.

Though this categorization isn’t an official staging system, it helps doctors choose the most appropriate treatments.

Pericardial Mesothelioma Stages

Pericardial mesothelioma is the least common form of this disease with only 150 or fewer cases ever identified. The majority of pericardial mesothelioma cases aren’t diagnosed until an autopsy is performed, making it very difficult for doctors to know exactly how it progresses.

Because it’s such as rare disease, pericardial mesothelioma doesn’t have an official staging system.

Instead, doctors can classify it as either early or advanced. However, an experienced mesothelioma specialist will still be able to assess pericardial mesothelioma patients on a case by case basis and determine appropriate treatments.

Mesothelioma Treatments for All Stages

Staging mesothelioma is an essential part of the diagnostic process. Not only is it a way for doctors to choose the most effective treatments, it’s also an important practice in building a personalized treatment plan for each patient.

Treating mesothelioma is a not a one-size fit all process. Each patient’s case must be looked at as a new disease requiring its own treatment approach. Staging systems help doctors become better at individualized care.

Additionally, diagnosing mesothelioma by stage also gives patients a better understanding of their condition. Doctors can take the information they’ve learned about the mesothelioma stage and communicate with their patients exactly what has happened and what to expect.

Mesothelioma is frequently misdiagnosed. If you’ve been diagnosed with mesothelioma, then it’s critical to get a second opinion from a specialist who can properly identify your disease stage.

By seeing a specialist with years of experience treating your exact type of mesothelioma, you can rest assured you’ll be getting the most effective treatments for your unique case.

For more information on seeing a mesothelioma specialist for treatments, contact the Mesothelioma Justice Network today.

View Author and Sources
  1. American Cancer Society, “Malignant Mesothelioma Stages.” Retrieved from: Accessed on January 1, 2018.
  2. Medscape, “Malignant Pleural Mesothelioma Staging.” Retrieved from: Accessed on January 1, 2018.

Last modified: April 3, 2019