Metastasis, or the spread, of mesothelioma plays an important role in the effectiveness of treatment options. A specialist may reverse the spread of mesothelioma with the right treatment.
Metastasis occurs when a mesothelioma tumor grows beyond the area where it initially formed. There are less treatment options the farther a tumor spreads. Slowing metastasis is the most important way to extend a patient’s life expectancy.
Key Factors Affecting Mesothelioma Metastasis
- Diagnosis - A mesothelioma diagnosis reveals whether the disease is advanced (metastatic) and how fast the disease is likely to spread. Patients diagnosed with early stage mesothelioma have more treatment options because the disease hasn’t spread too far. The patient’s cell type also impacts future metastasis; those with an epithelioid cell type experience slower disease progression and have more treatment options.
- Treatment - Most mesothelioma treatments hinge on the goal of limiting the disease’s ability to spread. Doctors use surgery to remove tumors before they spread to more tissue while radiation and chemotherapy kills newly replicating cells. Treatment focuses on pain relief for patients diagnosed with advanced mesothelioma.
- Prognosis - The key to prolonging a mesothelioma patient’s life is to prevent or slow metastasis. No matter what stage a patient is diagnosed at, there is almost always some form of treatment that can improve a prognosis. While patients can’t control their diagnosis, patients can improve their prognosis by seeking specialists and clinical trials.
Speak with a team member to explore your treatment options and find mesothelioma specialists near you.
What is Metastatic Mesothelioma?
Mesothelioma becomes metastatic when it spreads from the point of origination to other tissues and organs in the body. It spreads through the movement of microscopic cancer cells from the primary tumor to nearby areas where the cells eventually form new tumors.
Staging Metastatic Mesothelioma
Doctors describe the general growth of mesothelioma with a staging system that ranges from stages 1 to 4. Stage 1 and stage 2 mesothelioma are largely confined to the location of the primary tumor.
When mesothelioma spreads beyond the protective lining of the patient’s lungs, chest, or heart to other parts of the body, doctors consider the disease to be metastatic.
There are currently no official staging guidelines for mesothelioma, but most doctors use the TNM system. This system stages the metastasis of mesothelioma according to the growth of the tumor and its spread to organs or lymph nodes.
Stage 3 mesothelioma is technically the first truly metastatic stage of the disease. At this stage, mesothelioma has spread throughout one side of the body to nearby organs and body structures, like the lymph nodes and diaphragm.
Patients diagnosed with stage 3 mesothelioma may still be eligible for curative surgery. Eligibility for surgery depends on a number of factors, like the cell type and location of the tumor.
Stage 4 mesothelioma has spread to both sides of the body. At this point, mesothelioma cells may have spread to organs and structures far removed from the initial location of the tumor. Patients with stage 4 mesothelioma can take advantage of palliative treatment, which is designed to ease the pain and discomfort caused by symptoms of mesothelioma.
The Importance of Staging Mesothelioma
It’s important to understand why specialists use staging systems to describe metastatic mesothelioma.
Staging the spread of a tumor helps specialists determine the best course of treatment for their patient.
For example, early stage mesothelioma is localized to the lining of the organs and responds better to surgery and chemotherapy. Advanced (metastatic) mesothelioma has spread beyond the protective lining of the organs and is harder to remove surgically. Patients with advanced mesothelioma typically benefit more from palliative treatments that ease pain and discomfort.
Those diagnosed with late stage mesothelioma should also consider getting a second opinion. In some circumstances, a second opinion reveals a less advanced diagnosis, which opens up more treatment options to the patient.
How Does Mesothelioma Metastasize?
Microscopic mesothelioma cells travel from the initial tumor through the bloodstream or lymphatic system into tissues, organs, and other lymph nodes. The lymphatic system is a circulatory series of vessels throughout the body. Although similar to blood vessels, the lymphatic system is different in two important ways: it carries lymph (not blood) and it has nodes. Lymph is a colorless fluid that contains white blood cells. A certain points in the lymphatic system, there are nodes that can shut off the flow of lymph, filtering out toxins. The human body has hundreds of nodes where mesothelioma can spread to.
Once they reach their destination, mesothelioma cells can grow into a secondary tumors.
A process called angiogenesis, the creation of new blood vessels in the body, helps secondary tumors grow. Angiogenesis makes new blood vessels that connect to the growing tumor and provide it with blood and nutrients. This process plays an important role in the metastasis of mesothelioma tumors. Stopping it is one way researchers are currently approaching the fight against mesothelioma.
A drug called bevacizumab has promising results in clinical trials, and along with several other drugs, it is currently being researched as a possible treatment option.
Common Locations Where Mesothelioma Spreads
For patients with metastatic pleural mesothelioma, secondary tumors commonly appear in the:
- Lymph nodes
- Pericardium (the protective lining of the heart)
- Peritoneum (the protective lining of the abdomen)
- Chest wall
- Mediastinum (the space between the lungs)
For patients with metastatic peritoneal mesothelioma, secondary tumors commonly appear in the:
- Pleural cavities (the spaces between the lungs and the inside of the chest)
Metastasis and Cell Type
The cell type of a mesothelioma tumor plays an important role in how rapidly the disease spreads. Mesothelioma tumors made up of epithelioid cells metastasize more slowly than tumors made up of sarcomatoid cells.
Epithelioid cells are square-shaped and stick to each other as they spread, slowing down metastasis. Sarcomatoid cells, on the other hand, spread quickly in a haphazard pattern due to their spindle shape.
A mesothelioma tumor can also be biphasic, which means it’s made up of epithelioid and sarcomatoid cells. How quickly it spreads depends on the ratio of epithelioid to sarcomatoid cells. The more epithelioid cells a biphasic tumor has, the slower it metastasizes.
Treatment for Metastatic Mesothelioma
Generally speaking, patients with metastatic mesothelioma do not qualify for curative treatments because the tumor has spread too far for surgery or chemotherapy to be effective.
Doctors typically use palliative treatments to relieve pain and discomfort caused by symptoms of metastatic mesothelioma. However, patients may participate in clinical trials where researchers test new treatments, like immunotherapy, that can help improve survival time.
Our Patient Help Team can review your diagnosis and provide you with more information about clinical trials.