Stages of Mesothelioma
Like many other cancer types, mesothelioma is typically diagnosed with a stage number that describes its severity. Understanding a patient’s mesothelioma stage helps medical professionals develop a treatment plan with the highest potential for success. Pleural mesothelioma—which occurs in the lungs’ lining—has four stages based on the size of the original tumor and the extent of its spread. However, peritoneal mesothelioma, which occurs in the abdominal cavity’s lining, does not have an accepted staging system.
Last Updated:
- May 7, 2025
Key Facts About Pleural Mesothelioma Stages
Stage 1:
The cancer is localized and confined to the mesothelium.
Stage 2:
The cancer expands into the lung or diaphragm.
Stage 3:
The cancer spreads into the chest wall, the tissue surrounding the heart, or the lymph nodes in the chest.
Stage 4:
The cancer has spread to distant organs or tissues.
What Are the Stages of Pleural Mesothelioma?
There are four possible stages of pleural mesothelioma based on the TNM staging method.[1]
Stage 1
In stage 1 pleural mesothelioma, the cancer has not spread outside the mesothelium, the lining of the chest wall. It may develop in multiple spots inside the mesothelium but nowhere else, such as the lymph nodes or other organs. Typically, patients with stage 1 pleural mesothelioma have minimal symptoms, ranging from shortness of breath to a persistent cough to mild chest pain.
Stage 2
Stage 2 pleural mesothelioma is diagnosed when the cancer has spread beyond the mesothelium into the lung tissue or diaphragm, but not yet into the lymph nodes. Symptoms are more intrusive than in stage 1 and may include increased chest pain, difficulty breathing, fatigue, and fluid buildup in the pleural space.
Stage 3
When mesothelioma spreads into the space behind the breastbone, between the lungs, or into the lymph nodes in the chest, the cancer reaches stage 3. Patients with stage 3 pleural mesothelioma often experience worsening breathlessness, severe chest pain, weight loss, night sweats, and increased fatigue.
Stage 4
In stage 4 pleural mesothelioma, the tumor has invaded multiple areas, penetrating the pericardium or diaphragm, extending into the lymph nodes outside the chest, or spreading to other organs such as the heart, esophagus, liver, or opposite lung. This stage is the most severe form of mesothelioma, and patients may suffer symptoms including extreme difficulty breathing, intense pain, severe weight loss, loss of appetite, and overall decline in health.
How Mesothelioma Stage Affects Treatment Options
While staging mesothelioma makes it easier for doctors to communicate and give patients a prognosis, it also affects what treatment options may be available. A patient’s cancer stage is critical for identifying whether surgery, chemotherapy, radiation, immunotherapy, or clinical trials are the best route forward.
- Stage 1: This stage of disease is the most easily treatable and, as such, patients with stage 1 disease have the best prognosis.
- Stage 2: This stage of mesothelioma is often treated with surgery, chemotherapy, and radiation. As in stage 1, patients with stage 2 mesothelioma may be able to have their entire tumor removed surgically.
- Stage 3: As the cancer spreads further into stage 3, patients may receive treatments such as chemotherapy, immunotherapy, and palliative care.
- Stage 4: In the most severe stage of mesothelioma, patients often receive palliative care and immunotherapy and can potentially participate in clinical trials.
What Is Cancer Staging?
Cancer staging determines how much cancer is in a patient’s body and where it is located. There are four types of staging used in the TNM method[1], each used under the following circumstances:
- Clinical staging determines how much cancer is present based on a physical examination, imaging tests, and biopsies.
- Pathological staging is conducted after a tumor is surgically removed.
- Post-therapy staging determines how much cancer remains after a patient receives treatment.
- Recurrence staging determines the extent of the cancer if it returns after treatment.
Pleural mesothelioma patients may undergo one or more types of staging to determine whether they have stage 1, 2, 3, or 4 cancer, with stage 4 being the most severe.
Contact the Louisiana Mesothelioma Advocates
If you or a loved one has been diagnosed with mesothelioma after asbestos exposure—even if it was decades ago—you may be eligible for significant financial compensation. Contact Louisiana Mesothelioma Advocates, and our team will recommend the best mesothelioma physicians, and should you request, connect you with our sponsor, Baron & Budd, P.C., to protect your interests.
Mesothelioma is an aggressive cancer, and we urge you to act quickly. Call us at (504)-504-MESO or complete our online contact form today for a free consultation anywhere in Louisiana or across the country.
Content Reviewed by
Todd Kale
Todd Kale meets with mesothelioma patients and their families across Louisiana to investigate their asbestos exposure, providing compassionate support and guidance during a difficult time.
Cited Source
- American Joint Committee on Cancer. (n.d.). Cancer staging systems. American College of Surgeons. https://www.facs.org/quality-programs/cancer-programs/american-joint-committee-on-cancer/cancer-staging-systems/