What Affects Mesothelioma Metastasis?
As mesothelioma cells originating in the lining of vital organs begin to grow, a cell or small cluster of cells may break away from the point of origin and travel through the lymphatic system or bloodstream — eventually settling in another location.
Breakaway cells begin to replicate, and a new tumor grows. When mesothelioma cells form new tumors through metastasis, it is considered to still be mesothelioma and not a new form of cancer.
The good news is that treatments are available even after metastasis occurs — get our Free Mesothelioma Guide now to learn more.
Mesothelioma Cell Type
The cellular structure of mesothelioma also has an influence on where the cancer can spread to and how quickly the growth can occur.
There are two different types of mesothelioma cells: epithelioid and sarcomatoid. How far and how fast cancer spreads depends on which type of cancer cells a person has, or, in the case of biphasic cell mesothelioma (a combination of both epitheliod and sarcomatoid cells), which kind of mesothelioma cell is more dominant.
Epithelioid Mesothelioma Metastasis
Epithelioid cells are cube-like and uniform in appearance. When they do break off from the original tumor, they travel through the lymphatic system.
The lymphatic system is a part of the immune system, and it carries liquid and white blood cells throughout the body. However, the lymphatic system is filled with a series of nodes that filter and trap waste products and debris, such as a cluster of cancer cells.
The boxy shape of epithelioid cells causes this type of mesothelioma to spread slowly. Because of these characteristics, they tend to stay closer to the original cancer site and spread more through the lymphatic system.
Sarcomatoid Mesothelioma Metastasis
Sarcomatoid cells are large cylindrical cells that taper at two ends. The round, needle-like shape makes it easier for sarcomatoid cells to quickly travel through the body’s bloodstream or vascular system.
These cells can spread either through the lymphatic system or through the bloodstream. The vascular system does not contain gateways, like the lymph nodes, so the sarcomatoid cells can travel further away from their point of origin than they would be able to if they were moving in the lymphatic system.
Biphasic Mesothelioma Metastasis
In mixed-type or biphasic mesothelioma, the tumors are made up of a combination of both epithelioid cells and sarcomatoid cells. However, it’s not a 50/50 split between the two types.
The tumors will be made up of more than one kind of cell, and they will metastasize accordingly. If the tumors are made up of more epithelioid cells, then cancer will spread more slowly and stay more local.
But, if there are more sarcomatoid cells than epithelioid cells, then the disease will spread faster and farther.
Mesothelioma Metastasis Sites
The speed at which metastasis occurs, and how far away the new tumors can form, depends mainly on the cell structure of the patient’s mesothelioma.
Doctors can anticipate where the mesothelioma might spread to based on where it originated. Understanding potential patterns for spread allows doctors to know what other areas to monitor for new tumors.
It’s important to note that the lists of metastasis sites below are not exhaustive. While these sites are some of the most common locations for the growth of new mesothelioma tumors, the disease can also spread to other places throughout the body.
Pleural Mesothelioma Metastasis Sites
Pleural mesothelioma starts in the lining of the lung, known as the pleura. It is the most common form of mesothelioma and is caused by inhaling asbestos fibers.
Pleural mesothelioma can spread to the:
- Bones
- Chest lymph nodes
- Diaphragm
- Esophagus
- Liver
- Mediastinum (the space between the lungs)
- Muscles and ribs of the chest lining
- Opposite lung
- Thymus
- Trachea
One study even found pleural mesothelioma cells in a patient’s thigh muscles.
Peritoneal Mesothelioma Metastasis Sites
Peritoneal mesothelioma rarely leaves the abdomen. This is unlike pleural mesothelioma, which can travel throughout the body to a person’s liver.
Peritoneal mesothelioma can spread to:
- Other abdominal organs
- Liver
- Space between the lungs and the walls of the chest
- Spleen
- Tissue covering the small intestine and colon
Pericardial Mesothelioma Metastasis Sites
Pericardial mesothelioma is rare, and there is not much research or information out there about where the cancer might spread.
However, one area where pericardial mesothelioma is known to metastasize is the lungs.
Speak with our trusted patient advocates about treatment options for mesothelioma.
Mesothelioma Staging
There are four stages of mesothelioma. Each of these stages corresponds with how much the cancer has metastasized.
Stage 1 has the least amount of metastasis, and stage 4 has the highest amount. What stage of the disease a patient affects the type of treatment a patient can receive.
The most common staging system for pleural mesothelioma is the American Joint Committee on Cancer (AJCC) TNM system, which looks at the size of the original tumor (T), whether it has spread to any nearby lymph nodes (N), and if it has metastasized (M) to distant sites.
Other types of mesothelioma don’t have staging systems but can be informally staged by doctors.
Stages 1 and 2
In stages 1 and 2 of pleural mesothelioma, the cancer has only spread locally. Meaning, while the patient might have the disease in their diaphragm or local lymph nodes, it is still unilateral — that is it has remained on one side of the body.
In stages 1 and 2, most treatment methods like surgery are still viable options.
Stage 3
In stage 3 the disease has spread further. The disease may have spread to the esophagus, onto the surface of the pericardium, to the lymph nodes above the collarbone, or onto the other side of the body. In stage 3 it has not spread to a distant organ such as the liver or the other lung.
At this point, surgery might still be an option to remove the mesothelioma. However, patients will likely also receive chemotherapy or radiation therapy to improve their survival rate.
Stage 4
By stage 4 pleural mesothelioma, the cancer has spread further in the body to locations such as bones, the other lung, or the lining of the abdomen.
At this point, all treatments are palliative and designed to make the patient as comfortable as possible and to increase their life expectancy.
Metastasis and Prognosis
While metastasis and prognosis are inversely related (meaning that prognosis declines as the stage of mesothelioma increases), no two cases of mesothelioma are exactly alike. Statistics are not generally reliable in making an assumption about prognosis.
Each case of mesothelioma progresses at a unique rate, and no single treatment combination or modality is universally effective.
Only you and your doctor can make informed decisions about your treatment plan and your prognosis. What is certain is that a high level of patient comfort, and a positive outlook and attitude vastly improve both life expectancy and quality of life.
Our Free Mesothelioma Doctor Match is a program that matches you with mesothelioma specialists and cancer centers who can best treat your disease. We consider various factors, including location, experience, current health, and ability to travel.
Treatment for Advanced Stage Mesothelioma
While the current treatments are less effective the more the cancer has progressed, many clinical trials are looking into improving the standard of care or finding new mesothelioma treatment options. Right now, there is a significant focus on the benefits of immunotherapy and how doctors can teach the body’s lymphatic system to recognize and destroy mesothelioma cells.
Because each mesothelioma case is unique, it’s essential to get a second opinion from a mesothelioma specialist, when being diagnosed and looking at treatment options.
If you or a loved one has been diagnosed with mesothelioma, request our free mesothelioma guide for information about how we may be able to help you receive the financial compensation you deserve.
Common Question About Mesothelioma Metastasis
Where does mesothelioma spread first?
It depends. It is difficult for doctors to predict where mesothelioma will spread to first, as it can form in a number of different areas in the body. Mesothelioma can initially form in the lining of the lungs, abdomen, heart, or testes.
Some types of mesothelioma, such as peritoneal mesothelioma, typically spread to parts of the body that are adjacent to where the cancer originated.
Other types of mesothelioma, such as pleural mesothelioma, have a tendency to spread further throughout the body.
Does mesothelioma spread quickly?
Yes. Unfortunately, mesothelioma is an aggressive form of cancer. The majority of patients are diagnosed once the cancer has begun to spread throughout the body.
Thankfully, treatments are still available no matter how far your cancer has spread.
Can mesothelioma spread to bones?
Yes. While rare, pleural mesothelioma has been reported to spread to the bones. Doctors can recommend treatment options if mesothelioma has spread to your bones or other parts of your body.
