What is metastatic mesothelioma?

Metastatic mesothelioma occurs when cancerous mesothelioma cells spread from the original tumor site to other parts of the body, often causing advanced-stage cancer.

Does my mesothelioma cell type increase or decrease my chances of metastasis?

Yes. The cell type is one of the biggest factors contributing to metastasis. Epithelioid mesothelioma is the slowest-spreading cell, while sarcomatoid mesothelioma is the fastest-spreading cell type.

What effect does metastatic mesothelioma have on my prognosis?

People with metastatic mesothelioma typically have a shorter life expectancy due to the aggressive nature of the cancer. Once the cancer has metastasized, it is difficult to manage.

What treatment options are available to patients with metastatic mesothelioma?

Treatment for metastatic mesothelioma can be challenging due to significant spreading of the cancer. Most treatment options for metastatic mesothelioma patients include palliative treatments and immunotherapy drugs for pain management.

Written By: David Statman

Mesothelioma Metastasis

When mesothelioma tumors start growing uncontrollably, cancerous cells can begin to spread to other parts of the body. This is called metastasis. When metastasis of mesothelioma happens, it’s usually a sign of stage 3 or stage 4 cancer. Mesothelioma is staged by determining the size and amount of tumors, if there is evidence of cancer cells in nearby lymph nodes, and if the tumors have spread to distant areas of the body.

Medically reviewed for accuracy by

Dr. Stephen Williams

Precision Oncology Scientist

AI Summary of Mesothelioma Metastasis

Mesothelioma metastasis refers to the spread of cancer cells from their original location to other parts of the body. This process usually indicates that the disease has advanced, often reaching stage 3 or stage 4. When mesothelioma spreads, it can travel through nearby tissues, the lymphatic system, or the bloodstream, forming new tumors in organs such as the liver, bones, or adrenal glands. Understanding how and where this spread occurs helps provide a clearer picture of the disease's progression and impact.

What Is Metastasis?

Metastasis is the spread of cancer cells from the point of origin to other parts of the body. The farther the cancer cells spread, the more advanced the disease becomes. Preventing metastasis is the key to prolonging life expectancy, and the best way to prevent metastasis is with aggressive treatment. Finding a mesothelioma specialist gives you the best chances of extending your life. See our free Doctor Match program for more information and assistance in this search.

Factors Involved in Metastasis of Mesothelioma

There are a few main factors that impact metastasis of mesothelioma, or are the result of metastatic disease.

LOCATION AND CELL TYPE

Location in the Body
- Mesothelioma most often starts in the pleura (lining of the lungs), but it can also originate in the peritoneum (lining of the abdominal cavity), pericardium (lining of the heart), or tunica vaginalis (lining of the testes). The site of origin influences how and where the disease spreads.
Mesothelioma Cell Type
- Epithelioid mesothelioma is the most common type and generally metastasizes slower, which is why patients often have better outcomes.
- Sarcomatoid mesothelioma tends to spread more aggressively and is associated with shorter survival.
- Biphasic mesothelioma (mixed epithelioid and sarcomatoid cells) behaves in line with the cell type that is most prevalent.

TREATMENT CHALLENGES

As mesothelioma advances and spreads to distant sites such as the liver, adrenal glands, kidneys or bones, treatment options become more limited:

Surgery is typically not feasible once the disease has metastasized beyond the primary site, since removing widely distributed tumors will likely not control the disease.
Systemic chemotherapy (such as pemetrexed with cisplatin or carboplatin) and tumor treating fields (Optune Lua) can help slow disease progression.
Immunotherapy (immune checkpoint inhibitors like nivolumab and ipilimumab) has become a major option, especially for unresectable disease.
Supportive care is often integrated earlier in advanced cases to manage symptoms and improve quality of life.

EFFECTS ON PROGNOSIS

Extent of metastasis is one of the strongest predictors of mesothelioma patient survival. Greater metastatic burden is usually associated with shorter life expectancy.
Limited or no metastasis allows for more aggressive treatment approaches, such as surgery or multimodal therapy, offering the potential for longer-term disease control.
Once the disease has metastasized, the treatment goals shift toward slowing tumor growth, preventing further spread, and relieving symptoms, rather than attempting curative intervention.

Metastatic Mesothelioma

Mesothelioma tumors form in the linings of the lung, abdominal cavity, heart, or testes. As the disease progresses, the cancerous cells can migrate beyond the originating location. These microscopic cells travel through blood vessels, lymphatic channels, or by direct invasion, forming new tumors in nearby or distant organs. At this point, the disease is considered metastatic mesothelioma.

Importantly, when mesothelioma spreads to other organs such as the liver, bones, or adrenal glands, the cancer does not change its identity. For example, mesothelioma that spreads to the liver is still classified as mesothelioma, not liver cancer, because the tumor cells maintain their mesothelial origin.

Staging and Metastasis

The stage of mesothelioma reflects how far the disease has progressed. There are four stages of mesothelioma in the most commonly used systems (such as the TNM staging system for pleural mesothelioma):

Stage 1 and stage 2: Cancer remains localized to the pleura and surrounding tissue on one side of the chest.

Stage 3: Tumors have spread more extensively but have remained on one side of the chest and may now involve nearby organs (such as the lung, chest wall, pericardium, or diaphragm) and/or lymph nodes. This is often considered the point at which mesothelioma becomes regionally metastatic.

Stage 4: Cancer has spread (metastasized) to distant organs or tissues, potentially involving the liver, adrenal glands, kidneys, or bones. This is the most advanced form of mesothelioma.

Because mesothelioma grows in a diffuse sheet-like pattern rather than as a single solid tumor, staging is more complex than with many other cancers. Doctors may use different criteria or staging systems, particularly for peritoneal mesothelioma, where formal staging guidelines are less standardized.

Clinical Implications

Stage 1 and stage 2 mesothelioma: Aggressive treatments and multimodal therapies are considered depending on the patient’s overall health status (including surgery, chemotherapy, immunotherapy and radiation).

Stage 3 mesothelioma: At this stage, aggressive treatments — such as multimodal therapy (surgery, chemotherapy, immunotherapy and/or tumor treating fields) — may still be considered for select patients, especially those with epithelioid cell type and good overall health.

Stage 4 mesothelioma: The focus shifts primarily to systemic therapies (chemotherapy, immunotherapy, or clinical trials) and palliative care, aimed at managing symptoms, slowing the progression of the disease, and maintaining quality of life.

How Does Mesothelioma Spread?

Mesothelioma begins in the mesothelial linings of the body. These linings surround the lungs (pleura), abdominal cavity (peritoneum), heart (pericardium) and testes (tunica vaginalis). Once mesothelioma tumors form, malignant cells can spread in several ways:

Local Invasion

The most common form of tumor spread is directly into nearby tissues and organs. For pleural mesothelioma, this includes invasion of the lungs, chest wall, diaphragm and pericardium (lining of the heart). In peritoneal mesothelioma, the disease can invade any of the organs within the abdominal cavity, such as the colon, small intestines, liver or spleen.

Lymphatic Spread

Mesothelioma cells can enter the lymphatic system, which acts like a biological highway for cancer cells. Lymph nodes in the chest or abdomen may become involved, and from there, the disease can widely spread through the body.

Hematogenous (Bloodborne) Spread

Though less common, mesothelioma cells may travel through the bloodstream, leading to distant metastases in organs far from the original site.

Distant Metastasis

Historically, mesothelioma was considered a locally aggressive cancer rather than one that spread to distant areas of the body. However, with improved imaging and longer survival due to modern therapies, distant metastases are being identified more frequently. Documented metastatic sites include:

Brain
Bone
Liver
Adrenal glands
Ovaries (rare)

Although still uncommon compared with local progression, these distant sites confirm that mesothelioma has the potential to spread to locations throughout the body.

Symptoms of Mesothelioma Metastasis

Symptoms of mesothelioma worsen as tumors grow and spread. Therefore, symptoms of metastatic mesothelioma are often different or more intense than the symptoms of mesothelioma in early stages where tumors are still localized to the tissue linings.

Metastatic mesothelioma symptoms can be related to tumors affecting the liver, kidneys, brain or other areas of the body. Some symptoms of mesothelioma metastasis include:

Anemia (low red blood count)
Blood clots
Coughing up blood (hemoptysis)
Difficulty swallowing
Excessive sweating
Fever
Hoarseness
Laryngeal nerve palsy – Damage to a nerve in the throat, resulting in paralysis of the vocal cords
Muscle atrophy (muscle weakness)
Nerve issues in the arms, legs or spinal cord
Night sweats
Swelling of face or arms
Horner’s Syndrome – Facial and eye-related symptoms (on just one side of the face), such as an eyelid drooping, constricted pupil, decreased tear production, conjunctival redness and decreased sweating on the affected side

Cell Type and Metastasis

The histologic cell type of mesothelioma is one of the most important factors influencing how quickly the disease spreads and how it affects patient prognosis. Some cell types are more aggressive, leading to faster metastasis and shorter survival, while others progress more slowly and respond better to treatment.

Epithelioid Mesothelioma

Spread pattern: Epithelioid cells usually spread first to nearby organs and lymph nodes, often traveling through the lymphatic system.

Clinical behavior: This is the most common subtype accounting for 50%-70% of cases. It tends to metastasize slower than other forms, is easier to recognize in microscopic analysis of tissue and fluid samples, and is more responsive to surgery and multimodal therapy.

Prognosis: Patients with epithelioid disease generally have the longest survival times, with median survival reported at 18-24 months in recent studies when treated with aggressive therapy.

Sarcomatoid Mesothelioma

Spread pattern: Sarcomatoid tumors tend to invade locally and spread through the bloodstream rather than the lymphatic system, which allows cancer cells to reach distant organs.

Clinical behavior: This subtype accounts for about 10%-20% of cases, is more difficult to identify in microscopic analysis of tissue and fluid samples, and is the most aggressive with rapid growth and poor response to surgery or chemotherapy.

Prognosis: Sarcomatoid mesothelioma is associated with the shortest survival – typically less than 1 year.

Biphasic Mesothelioma

Spread pattern: Biphasic tumors contain both epithelioid and sarcomatoid cells. This subtype tends to spread with wide local invasion to nearby organs and tissues but can also spread through the lymphatic system and bloodstream.

Clinical behavior: This combination cell type accounts for approximately 20-35% of mesothelioma cases. The aggressive nature often depends on the dominant cell type but tends to be more aggressive than epithelioid and less aggressive than sarcomatoid.

Prognosis: Overall survival typically depends on the ratio of epithelioid to sarcomatoid cells; prognosis is often worse with a greater percentage of sarcomatoid cells.

Treating Metastatic Mesothelioma

As mesothelioma advances and spreads beyond the site of origin, treatment options become more limited. Once the cancer reaches distant organs — such as the brain, liver or bones — mesothelioma surgery is rarely an option.

In these cases, removing the primary tumors does little to control widespread disease, and surgery can be difficult and significantly reduce quality of life. For example, removing a diseased lung provides minimal benefit if mesothelioma has already metastasized to other organs.

In late-stage mesothelioma, treatments often focus on slowing disease progression, extending survival when possible, managing symptoms, and improving the patient’s quality of life. Key approaches are below.

Systemic Therapies

Chemotherapy

The standard mesothelioma chemotherapy combination of pemetrexed with a platinum-based agent (cisplatin or carboplatin) is approved by the U.S. Food and Drug Administration (FDA).

Immunotherapy

The FDA approval of nivolumab (Opdivo) plus ipilimumab (Yervoy) provided the first mesothelioma immunotherapy for patients. This approach has improved survival.

Tumor treating fields (Optune Lua)

The FDA approved a tumor treating fields device called Optune Lua for the treatment of pleural mesothelioma when used alongside chemotherapy.

Clinical Trials

Patients with advanced mesothelioma are often encouraged to consider clinical trials, which can provide access to new and promising treatment options or new combinations of surgery and other therapies:

Novel immunotherapies (e.g., CAR T-cell therapy or oncolytic viruses)
Targeted therapies for specific genetic variations
Combinations of systemic drugs with or without surgery

Palliative and Supportive Care

Palliative care should be initiated and maintained throughout the treatment process for all mesothelioma patients. Maintaining quality of life for patients should always be a priority.

Examples of palliative care for mesothelioma include:

Pain management with medications, nerve blocks or palliative radiation
Procedures to improve symptoms such as draining pleural effusions or peritoneal fluid to reduce shortness of breath and abdominal pain
Nutritional support and physical therapy to improve strength and quality of life
Hospice care when treatments are no longer effective, focusing on comfort and dignity

Frequently Asked Questions About Metastatic Mesothelioma

What defines mesothelioma metastasis?

Mesothelioma metastasis is defined as the distant spread of mesothelioma tumors and cells. Mesothelioma starts in the tissue lining of the lungs, abdominal cavity or heart. When tumors spread past this lining, they can reach nearby organs such as the lungs or spleen. When they spread beyond the site of origin, this is considered metastasis.

What is the stage of mesothelioma when metastasis occurs?

Metastasis is often found in the later stages of mesothelioma: stage 3 and stage 4. Stage 4 mesothelioma is defined as the distant spread of tumors beyond the regional area of the abdominal cavity or chest cavity.

How do doctors determine if mesothelioma has metastasized?

Doctors conduct imaging scans on the patient to find abnormal masses in distant areas, such as the spinal cord or brain. They then perform fluid or tissue biopsies to determine if cancer cells exist. This is how doctors can tell if mesothelioma has metastasized.

How does mesothelioma metastasize?

Mesothelioma metastasizes by spreading with direct contact to nearby organs, through the bloodstream or lymphatic system. Cancer cells can travel to lymph nodes near the original site and quickly spread to other parts of the body. The lymphatic system is sort of a highway system of the body. The bloodstream is the other primary method of metastasis.

How is mesothelioma treated after metastasis?

When mesothelioma has metastasized, the prognosis is usually poor. Surgery is often not an option since removing primary tumors will not help the patient when cancer also exists in other areas of the body. The most common ways to treat mesothelioma metastasis are with chemotherapy, immunotherapy, targeted therapies in clinical trials, and palliative care. Patients are provided with pain relief treatments throughout their cancer journey to reduce symptoms, increase comfort, and improve quality of life.

Sources & Author

Malignant Mesothelioma Treatment (Adult). Vanderbilt-Ingram Cancer Center. Retrieved from: https://vicc.org/cancer-info/adult-malignant-mesothelioma. Accessed: 09/27/2025.
Mesothelioma Stages. American Cancer Society. Retrieved from: https://www.cancer.org/cancer/types/malignant-mesothelioma/detection-diagnosis-staging/staging.html. Accessed: 09/27/2025.
Patterns of metastases in malignant pleural mesothelioma in the modern era: Redefining the spread of an old disease. Journal of Clinical Oncology. Retrieved from: https://ascopubs.org/doi/10.1200/JCO.2017.35.15_suppl.8556. Accessed: 09/272025.
Malignant Mesothelioma Treatment (PDQ®)–Patient Version. National Cancer Institute. Retrieved from: https://www.cancer.gov/types/mesothelioma/patient/mesothelioma-treatment-pdq. Accessed: 09/27/2025.

About the Writer, David Statman

David Statman is a Content Writer for Mesothelioma Guide. He received both his bachelor's and master's in journalism from West Virginia University, and has been in medical publishing since January 2022. He previously worked in sports journalism, primarily reporting on West Virginia sports for a number of publications.

He lives in Delaware with his wife, dog and two cats, and avidly competes as a professional wrestler in the Philadelphia area.