Mesothelioma Stages

Expert Fact Checked

This page was medically reviewed by James Stevenson, M.D. on February 6, 2019. For information on our content creation and review process read our editorial guidelines. If you notice an error or have comments or questions on our content please contact us.

James Stevenson, M.D. Thoracic Medical Oncologist

Mesothelioma has four stages used to determine cancer progression and treatment options. Stage 1 mesothelioma has a better prognosis than stage 4, when the cancer is more advanced. Symptoms are also less noticeable in the early stages, becoming more prominent by stage 3.

01. Stages of Mesothelioma

What Are the Stages of Mesothelioma?

Doctors classify malignant mesothelioma into four main stages. Stages of mesothelioma indicate how far the cancer has progressed in the body. During mesothelioma diagnosis, a doctor will determine whether the cancer is stage 1, 2, 3 or 4. Stage 4 is the most advanced stage of malignant mesothelioma. Most commonly, patients are diagnosed after stage 1.

Pleural Mesothelioma Stages

  • Stage 1: The tumor is localized to the mesothelial lining and has not spread.
  • Stage 2: Cancer has spread to nearby organs, such as the lung or diaphragm.
  • Stage 3: Cancer cells have spread to nearby tissues, lymph nodes and/or organs.
  • Stage 4: Cancer has spread to nearby and distant organs, tissues and lymph nodes.
The Four Stages of Mesothelioma

An illustration of the 4 stages of mesothelioma

Staging does not change as the disease progresses. If a tumor grows or shrinks in size, the stage remains the same. Patients may hear doctors reference metastasis when cancer grows or spreads to other parts of the body. In the later stages of disease, symptoms are more recognizable and may worsen. Patients with stage 3 or 4 mesothelioma also tend to have shorter life expectancies than those diagnosed at an earlier stage.

Medical professionals use a variety of diagnostic tests to determine the cancer stage. Doctors evaluate tumor location, size and extent of disease spreading during the staging process.

02. Mesothelioma Staging

How Is Mesothelioma Cancer Staged?

Staging refers to the process of categorizing malignant mesothelioma according to the extent of the disease in a patient’s body. Staging is a process applied to all types of cancer. Specific staging systems are often developed based on characteristics of specific cancers. Pleural mesothelioma is the only type of this cancer that has specific staging systems.

Mesothelioma staging occurs during the initial diagnosis. Mesothelioma doctors often rely on general cancer staging characteristics to stage the disease. The American Joint Committee on Cancer’s AJCC Cancer Staging Manual is most commonly cited.

Pleural Mesothelioma Staging

Pleural mesothelioma is the only type that has unique mesothelioma staging systems. These systems include the Butchart, Brigham and Tumor, Nodes and Metastasis (TNM) staging systems. All of these staging systems indicate patients diagnosed at the early stages have more treatment options and a more favorable prognosis.

Stages of Pleural Mesothelioma

An illustration of stage 1 mesothelioma

An illustration of stage 2 mesothelioma

Stage 3 Mesothelioma Illustration

An illustration of stage 4 mesothelioma

TNM Staging System

The TNM staging system was developed by French physician Pierre Denoix in the 1940s. It is the most common staging system used for mesothelioma.

The TNM staging system is frequently updated according to new mesothelioma research. To classify pleural mesothelioma stage, doctors look at:

  • Tumor size and extent
  • Lymph node involvement
  • Metastasis to other parts of the body

Staging Pleural Mesothelioma With the TNM Staging System

Stage 1

The cancer is only affecting one layer of the pleura (lining of the lungs). Mesothelioma may have spread to the pericardium (lining of the heart), diaphragm and/or lung.

Stage 2

Mesothelioma has spread to both layers of the pleura but is still localized to one side of the body. Mesothelioma may have spread to nearby lymph nodes.

Stage 3

Mesothelioma has spread to the chest wall, esophagus, diaphragm and/or lymph nodes. The cancer may have also spread to nearby lymph nodes on both sides of the body. Mesothelioma has not spread to distant parts of the body at this stage.

Stage 4

Mesothelioma has spread to distant organs through the bloodstream. The cancer may impact the liver, bones or brain.

This system also breaks down the four stages even further to include stages 1A, 1B, 3A and 3B. Doctors updated the TNM system with these additional stages in January of 2018. The six stages of the updated system make it easier to estimate mesothelioma prognosis. The additional stages also help doctors choose the most effective treatment option for each patient.

Butchart Staging System

Proposed in 1976, the Butchart System is the oldest formal mesothelioma staging system. The system is only used to stage pleural mesothelioma. In this system, the location of the primary tumor mass determines the stage. This system is not commonly used today.

This mesothelioma staging system does not take into account:

  • The size of the tumor
  • The number of cancer cells present
  • The overall level of cancer in the body

Staging Pleural Mesothelioma With the Butchart Staging System

Stage 1

The cancer is localized to one side of the pleura (lung linings). Some patients may have tumors on the pericardium (heart lining) or the abdominal cavity.

Stage 2

The cancer has grown into the chest wall and may be on both sides of the pleura. At this stage, the cancer has often spread to the esophagus and lymph nodes within the chest.

Stage 3

The cancer has spread to the abdominal cavity and can often be found in lymph nodes outside of the chest.

Stage 4

Mesothelioma has spread to distant organs through the bloodstream. Affected organs may include the liver, brain or bones.

Brigham Staging System

In 1993, while working at the Brigham & Women’s Hospital, Dr. David Sugarbaker and several colleagues developed the Brigham staging system. They created the system through collaboration with the Dana-Farber Cancer Institute. Initially, the system was based on clinical experience with 52 patients. In 1998, it was updated based on a larger sample size.

The Brigham staging system emphasizes surgery as a mesothelioma treatment option.

Staging Pleural Mesothelioma With the Brigham Staging System

Stage 1

At this stage, there is no lymph node involvement. The pleural mesothelioma tumors may be surgically removed.

Stage 2

Mesothelioma has spread to the lymph nodes, but surgery remains a viable treatment option.

Stage 3

The cancer has spread into the chest wall, peritoneum (lining of the abdomen) and/or heart. Surgery is no longer a treatment option.

Stage 4

Mesothelioma has spread through the bloodstream. Because the cancer may have spread to the liver, brain, lymph nodes and bones, surgery is not a viable option.


Peritoneal, Pericardial and Testicular Mesothelioma Cancer Staging

Peritoneal, pericardial and testicular mesothelioma do not have their own unique staging systems.

Doctors may stage peritoneal mesothelioma patients using the Peritoneal Cancer Index (PCI). This staging system classifies disease according to tumor size. A higher score is given to extensive cases, which have a less favorable prognosis.

Some mesothelioma doctors may use a modified version of the pleural mesothelioma TNM system to stage peritoneal mesothelioma patients. This staging system is not yet widely accepted within the medical community. However, studies suggest the peritoneal mesothelioma TNM staging system predicts patient prognosis most accurately.

Because they are rare, pericardial mesothelioma and testicular mesothelioma do not have their own staging systems. There is not enough data from case studies to accurately stage patients.

  • There are fewer than 50 pericardial mesothelioma diagnoses in the United States each year.
  • There have been approximately 100 cases of testicular mesothelioma described in medical literature.

SEER Staging System

The Surveillance, Epidemiology and End Results (SEER) Program from the National Cancer Institute (NCI) also developed staging classifications. The SEER Program developed two staging classifications. They are called summary staging and extent of disease coding. These classify stages based on local, regional or distant spread of cancer.

The system is applicable for many cancer sites, so it may be helpful in mesothelioma. However, doctors do not typically use the SEER staging system to categorize their patients’ cancers. The system may be part of cancer research efforts and tumor registries.

03. Mesothelioma Treatment by Stage

How Mesothelioma Stage Impacts Treatment and Prognosis

An individual’s mesothelioma stage has a direct impact on the recommended treatment options. Mesothelioma stage is also an important factor in a patient’s prognosis. Mesothelioma patients diagnosed at stage 1 or 2 often have the most treatment options available. During the early stages, the disease is still localized and the patient is in better health. As a result, early-stage diagnosis typically allows for aggressive treatments, such as surgery, and has a more favorable prognosis.

Mesothelioma treatment options for those with late-stage diagnoses are often more limited. By stage 3 or 4, the cancer has spread to other areas of the body and patient health may be declining. Advanced-stage patients often undergo palliative treatments to reduce symptoms and potentially extend life expectancy.

Understanding Palliative Mesothelioma Treatment

Palliative care is treatment administered with the intention of relieving symptoms. These symptoms may be the result of the mesothelioma cancer or side effects caused by other forms of treatment.

Learn MoreLearn More About Mesothelioma Palliative Care

Doctors will also consider other factors when determining mesothelioma cancer treatment plans. In addition to stage, mesothelioma type and cell type affect treatment options. Doctors will also consider a patient’s existing conditions, age and overall health.

Regardless of stage, patients may be eligible to take part in clinical trials at mesothelioma cancer centers. Treatments such as immunotherapy and gene therapy have shown success in clinical trials.

Patients should discuss their individual case with their doctor to understand all treatment options available.

Stage 1 Mesothelioma Treatment

Cytoreductive surgery is typically the recommended course of treatment for stage 1 mesothelioma patients. At this early stage, doctors perform surgery to remove as much of the cancer as possible. Pleural mesothelioma patients often undergo extrapleural pneumonectomy or pleurectomy/decortication.

Stage 1 peritoneal mesothelioma patients may be treated with hyperthermic intraperitoneal chemotherapy (HIPEC). This is a form of chemotherapy applied during surgical procedures.

Mesothelioma patients diagnosed in stage 1 may also be treated with radiation therapy. Doctors may also recommend intravenous chemotherapy drugs, such as pemetrexed and cisplatin.

Stage 2 Mesothelioma Treatment

Patients diagnosed with stage 2 mesothelioma have many treatment options. Multimodal treatment is a widely accepted option for stage 2 patients. The therapy commonly includes a combination of surgery, chemotherapy and/or radiation.

At this stage, the viability of surgery depends on:

  • Metastasis (spreading of disease)
  • Patient health

Multimodal plans may also incorporate emerging treatments such as immunotherapy. However, therapies will vary according to individual cases. Multimodal therapy may not be an option for all stage 2 patients. Doctors will determine viable options on an individual basis.

Stage 3 Mesothelioma Treatment

Treatment options for stage 3 mesothelioma patients are primarily palliative. These treatments focus on prolonging life and improving a patient’s quality of life. At this stage, physicians commonly recommend chemotherapy and radiation to improve patient comfort.

Surgery to remove tumors often involves too many risks for stage 3 patients. But physicians commonly use minor surgical procedures to drain fluid and ease symptoms. Pleurocentesis and paracentesis are common palliative surgeries administered at this stage.

Stage 4 Mesothelioma Treatment

Treatment plans for stage 4 mesothelioma patients largely focus on palliative treatments. At this advanced stage, physicians design treatment plans to manage symptoms, prolong life and improve quality of life.

Patients with stage 4 mesothelioma may undergo systemic chemotherapy, radiation and/or palliative surgery to mitigate symptoms.

New Mesothelioma Treatments Available to All Stages

Mesothelioma researchers use clinical trials to investigate new treatment options for early- and late-stage patients. One study from 2019 analyzed how adding a compound to chemotherapy could increase the efficacy of the treatment. Other recent clinical trials observed the impact of a new application of chemotherapy on patients with advanced-stage peritoneal mesothelioma. The new application studied was bidirectional chemotherapy. Researchers found it improved the 2-year survival rate to about 83% for some patients.

Ongoing clinical trials continue to test new treatments for all stages of mesothelioma.

04. Common Questions

Common Questions About Mesothelioma Cancer Stages

How fast does mesothelioma progress?

Mesothelioma may progress quickly once diagnosed, but symptoms can take years to develop. Mesothelioma has a long latency period. It may take 10 to 50 years before symptoms present. Many factors can impact the latency period, such as age at first exposure to asbestos. Latency period and other factors can impact early mesothelioma diagnosis. When diagnosed early, treatment may be more effective.

How does staging impact a mesothelioma diagnosis?

Doctors will determine the mesothelioma stage during diagnosis. It is one of several factors that doctors will consider when determining a patient’s treatment plan. The stage of mesothelioma also impacts a patient’s prognosis, or the likely course of the disease.

Which staging system is used to stage pleural mesothelioma?

The TNM staging system is the most commonly used for pleural mesothelioma. The TNM system assesses tumor extent, lymph node involvement and metastasis. Doctors use this staging system to help determine the best treatment options for a patient’s case.