Medically Reviewed By
Karen Ritter, RN BSN
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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 metastasis.
- Location and cell type – The cell type and origin of a patient’s disease affect how fast mesothelioma will spread. For instance, in pleural mesothelioma, sarcomatoid cells metastasize faster than epithelioid cells.
- Treatment challenges – The farther mesothelioma spreads, the more challenging treatment becomes. Advanced mesothelioma is difficult to treat as it has metastasized and spread to other organs, affecting the patient’s overall health. Patients whose mesothelioma has metastasized may not be strong enough for aggressive surgeries, or surgery may not be effective due to the far reaching spread of the disease in the body. However, there are available treatments that have the ability to slow down the metastatic process.
- Effect on prognosis – A patient’s prognosis, or life expectancy, is inversely proportional to metastasis: Greater metastasis typically means a shorter life expectancy. Little to no metastasis usually gives more hope for a longer survival through aggressive treatment. Once the disease has metastasized, the goal of treatment is to stop tumor growth, prevent further metastasis and to ease the patient’s symptoms.
Once mesothelioma tumors have formed, the microscopic cells that make up the tumor can spread to other organs and throughout the body. These cells form new tumors in other parts of the body. At this point, the mesothelioma is considered metastatic.
When mesothelioma spreads to a different organ, it is still considered mesothelioma. For example, mesothelioma that has spread to the liver is not considered liver cancer. The cells in the newly developed liver tumor tumor are still mesothelioma cells.
Metastasis corresponds with how advanced the mesothelioma is, which is denoted by staging. There are four stages of mesothelioma: Stage 3 and stage 4 are characterized as metastatic mesothelioma.
Stage 3 Mesothelioma From Metastasis
Stage 3 mesothelioma is still confined to one side of the body but tumors have spread, or metastasized, to nearby organs and lymph nodes.
Stage 4 Mesothelioma
Stage 4 mesothelioma has metastasized within the body and has invaded multiple, possibly distant, organs. This is the most advanced form of mesothelioma.
Typically, the extent of a patient’s metastasis is used to estimate how advanced the cancer is, but mesothelioma is challenging to stage due to the complexity of the cancer. It is important to note that different doctors may use different criteria for determining the stage of the cancer.
How Does Mesothelioma Spread?
Mesothelioma cells can metastasize to both local and distant organs. Localized metastasis happens when mesothelioma cells continue to grow uncontrollably and attach to nearby organs.
The main channels of metastasis, however, are the blood vessels and lymphatic system. These systems are like an interstate for mesothelioma cells and are responsible for the distant metastasis of mesothelioma.
Distant metastasis is rare, but it is possible. Mesothelioma originates on the outer linings of the lung or abdominal cavities and begins invading those local areas first.
When these cells reach the blood and lymphatic vessels, they can then travel to other areas of the body and form new tumors. Though rare, there have been cases of mesothelioma spreading to the:
- Adrenal glands
Mesothelioma and the Lymphatic System
The lymphatic system is structurally similar to the vascular system (blood vessels). The lymphatic system is a sort of biological highway that helps immune cells respond to infections, diseases and more.
The lymphatic system consists of lymph nodes designed to trap harmful cells and bacteria. These nodes act like checkpoints for most cancers, including mesothelioma, and are an essential component of the immune system. However, cancer can use the lymphatic system to travel through the body and cause metastasis.
Swollen lymph nodes may be a sign of metastatic mesothelioma, because cancer cells can infiltrate the lymphatic system.
Cell Type and Metastasis
The cell type of a mesothelioma patient is one of the biggest factors in how fast metastasis occurs. Some patients experience more rapid metastasis due to a more aggressive cell type. Metastasis also affects a patient’s prognosis. The faster mesothelioma spreads, the faster it can overtake the patient’s body.
Epithelioid mesothelioma cells spread to nearby organs and lymph nodes and may continue to spread through the lymphatic system. Epithelioid mesothelioma is the slowest-spreading cell type and easiest to treat with surgery.
Sarcomatoid mesothelioma tumors themselves grow faster and larger, spreading mostly through the blood vessels rather than the lymphatic system. Sarcomatoid mesothelioma is the fastest-spreading cell type and toughest to treat with surgery. Sarcomatoid mesothelioma has the worst prognosis for these reasons.
Biphasic mesothelioma is made up of both epithelioid and sarcomatoid cell types but will typically take on the characteristics of the most prevalent cell type. This means biphasic mesothelioma with mostly epithelioid cells metastasizes slower. Biphasic mesothelioma with mostly sarcomatoid cells metastasizes quickly.
Treating Metastatic Mesothelioma
Treatment options for advanced mesothelioma become more limited the farther the disease spreads. For instance, most surgeons won’t remove a lung if mesothelioma has spread to the brain. The benefit of removing the lung is minimal, while the patient may experience issues with only having one lung.
Generally, treatment options at this point are palliative and designed to make the patient comfortable by managing pain levels.
Palliative Treatment for Mesothelioma Metastasis
Palliative treatments are used to ease the symptoms associated with mesothelioma. Most of these symptoms range from shortness of breath to chest pain and can be solved with minor procedures involving the drainage of excessive lung or abdomen fluid. There are also palliative forms of chemotherapy and radiation. They’re lower doses of each, minimizing side effects but slowing the spread of tumors.
Studies show that patients with metastatic cancer who underwent palliative treatments tend to live longer.
New Therapies for Patients With Mesothelioma Metastasis
Aggressive treatments, like surgery, aren’t used as often in advanced cases, but there are many new drugs in development to inhibit the metastasis of mesothelioma. Examples include immunotherapy and other targeted therapies, such as VEGF inhibitors.
Exploring clinical trials for advanced mesothelioma can open new pathways for treatment and improve life expectancy. Connect with the top cancer centers to see a list of clinical trials, and find one you match with that has openings.
Top Cancer Centers
Brigham and Women's Hospital
Moffitt Cancer Center
UCLA Medical Center
Los Angeles, CA
Frequently Asked Questions About Metastatic Mesothelioma
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.
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