01. Stages of Mesothelioma
What Are the Four Stages of Mesothelioma?
Doctors classify malignant mesothelioma into four main stages.
The Four Stages of Mesothelioma
During 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.
- Stage 1: The tumor is localized to the mesothelial lining and has not spread.
- Stage 2: The 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.
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. How Is Mesothelioma Staged
How Is Mesothelioma Staged?
Mesothelioma 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, although specific staging systems are often developed based on characteristics of specific cancers, like mesothelioma.
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 staging and TNM systems. Despite their differences, all of the staging systems indicate patients diagnosed at the early stages have more treatment options and a more favorable prognosis.
Stages of Pleural Mesothelioma
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 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
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.
The cancer has grown into the chest wall and may be on both sides of the pleura (lung linings). At this stage, the cancer has often spread to the esophagus and lymph nodes within the chest.
The cancer has spread to the abdominal cavity and can often be found in lymph nodes outside of the chest.
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. The system was created 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
At this stage, there is no lymph node involvement and the pleural mesothelioma tumors may be surgically removed.
The mesothelioma has spread to the lymph nodes, but surgery remains a viable treatment option.
The cancer has spread into the chest wall, peritoneum (lining of the abdomen) and/or heart. Surgery is no longer a treatment option.
The 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.
TNM Staging System
The Tumor, Nodes and Metastasis (TNM) staging system was developed by French physician Pierre Denoix in the 1940s. Since then, it has been adjusted for many specific cancers. The first mesothelioma-specific TNM staging system was developed by A. P. Chahinian in the early 1980s.
Most doctors use this system, and it 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
The cancer is only affecting one layer of the pleura. Mesothelioma may have spread to the pericardium, diaphragm and/or lung.
The 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.
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.
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 patient prognosis. The additional stages also help doctors choose the most effective treatment option for each patient.
Peritoneal, Pericardial & Testicular Mesothelioma Staging
Peritoneal, pericardial and testicular mesothelioma do not have their own unique staging systems.
Peritoneal mesothelioma patients may be staged 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, according to studies, the peritoneal mesothelioma TNM staging system predicts patient prognosis most accurately.
- 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.
Resources for Mesothelioma Patients
03. Treatment by Stage
How Mesothelioma Stage Impacts Treatment
An individual’s mesothelioma stage has a direct impact on the recommended treatment options. 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.
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
In addition to stage, mesothelioma type and cell type impact treatment options. Doctors will also consider a patient’s existing conditions, age and overall health when determining treatment plans.
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, surgery is used 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), a form of chemotherapy applied during surgical procedures.
Mesothelioma patients diagnosed in stage 1 may also be treated with radiation therapy or 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 radiation.
At this stage, the viability of surgery depends on:
- Metastasis (spreading of disease)
- Patient health
Multimodal plans may also incorporate emerging treatments like immunotherapy. However, therapies will vary according to individual cases and may not be an option for all stage 2 patients. Multimodal therapy may not be an option for all stage 2 patients. Doctors will determine viable options on an individual basis. Incorporated therapies vary according to individual cases and may not be an option for all stage 2 patients.
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.
Surgical resection 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 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 use systemic chemotherapy, radiation and 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 (bidirectional chemotherapy) on patients with advanced-stage peritoneal mesothelioma. The bidirectional chemotherapy 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.