There are different mesothelioma cell types and each can determine treatment, staging and prognosis. Epithelioid mesothelioma is the most treatable cell type, but there are specific options available for each.
What Are the Different Mesothelioma Cell Types?
The type of mesothelioma you have can make a big difference in treatment. Cell type also plays a big part in your life expectancy. Mesothelioma cells develop in different ways, with some types dividing and spreading through the body quickly, and others more slowly. Slower moving cancer cells mean a longer life. They are also more treatable.
The three mesothelioma cell types are:
Most veterans with mesothelioma are diagnosed with epithelioid cell type. This cell type comes with the best prognosis. If you have a more rare type, there are mesothelioma specialists in the VA and private hospitals across the country who can help.
Epithelioid mesothelioma is the most common type of mesothelioma. It makes up about 50-70% of all cases.
Epithelioid mesothelioma comes with a better survival rate than other cell types. This type of mesothelioma has also had the most research done on it, so there is a better understanding of what kind of treatment is the most effective.
Cell Description and Behavior:
- Clearly visible nuclei
- Cuboid shape
- Clumps together
- Spreads slower than other cell types
Epithelioid mesothelioma cells are mutated epithelial cells. Everyone has epithelial cells that line different kinds of tissues, such as pleural tissue. These cells sense things in the environment and protect and lubricate vital organs. You have these cells in virtually all parts of your body, including your skin and internal organs.
Epithelioid cells are more common in those with pleural, rather than peritoneal, mesothelioma.
Doctors must get a tissue sample through a needle or surgical biopsy to diagnose this cell type. Under a microscope, the cancerous cells can be identified as epithelioid cells. However, epithelioid cells can look like other types of cancer. Doctors must be aware of a potential mesothelioma diagnosis to avoid misdiagnosis.
If you don’t know if you have epithelioid mesothelioma, ask your doctor to give you a copy of your pathology report. This is a detailed explanation of your diagnosis, describing what the cells look like.
In 2017, there was a study of 19 patients with advanced epithelioid mesothelioma. Their cancer hadn’t spread to nearby lymph nodes. They were all in stage 3 or 4 pleural mesothelioma. The median survival time for this diagnosis is 16 and 12 months respectively. But these 19 patients received pleurectomy with decortication surgery to remove their tumors. The overall survival of this group was 7.3 years, about 7 times the average survival time.
Sarcomatoid mesothelioma is the least common. It’s also the most difficult to treat. It often looks like other types of cancer under the microscope, making it difficult to diagnose.
Only about 7-20% of all cases of mesothelioma are a sarcomatoid type. Other names for this cancer include “spindled mesothelioma” and “diffuse malignant fibrous mesothelioma”.
Sarcomatoid cells are cube-shaped like epithelioid cells. Sarcomatoid cells in mesothelioma are elongated, large and spindle-shaped.
Cell Description and Behavior:
- Long, spindly shape
- Larger nuclei
- Spreads faster than other cell types
Sarcomatoid mesothelioma can be of the pleural or peritoneal type. Like epithelioid mesothelioma, it’s caused by asbestos. Sarcomatoid mesothelioma is very aggressive and spreads easily. It often looks like other cancers, even benign conditions such as fibrous tumors of the lining of the lung. It can also look like sarcoma, which is a type of cancer affecting many other body areas.
There aren’t as many effective treatment options for sarcomatoid mesothelioma, and patients don’t respond as well to the available treatments compared to epithelioid mesothelioma.
Doctors begin their diagnosis of this cell type with CT scans of the chest or MRI scans. If the scan looks like cancer, the doctor takes a biopsy. A common biopsy procedure is a thoracoscopy. This is a way to see the lung tissue using a camera and a flexible tube. After that, doctors examine the sample under a microscope to determine cancer and cell type.
Doctors sometimes use immunohistochemistry to confirm sarcomatoid mesothelioma. This is a test that looks for antibodies specific to certain cancer cells. Sarcomatoid mesothelioma cells have unique antibodies. Doctors use special stains that stick to these antibodies, making microscopic examination more accurate.
Common symptoms of sarcomatoid mesothelioma include:
- Unexplained weight loss
- Shortness of breath
- Nausea and a lack of appetite
- Swelling of the abdomen
The treatment of sarcomatoid mesothelioma depends on the stage and cancer location. Surgery, radiation therapy and chemotherapy are the traditional treatment methods.
Studies suggest that the median survival rate for sarcomatoid mesothelioma is about 6 months. Keep in mind that this is a median. That means one-half of sarcomatoid patients live beyond this mark. The treatment you receive is also a strong determinant of your survival time.
Biphasic mesothelioma has a combination of epithelioid and sarcomatoid cancer cells. The more epithelioid cells you have in the mixture, the longer your time of survival is likely to be.
Biphasic mesothelioma is the second most common kind of mesothelioma. It makes up about 20-35% of all mesothelial cancers. Most of the biphasic mesothelioma patients have disease within the pleural lining of the lung. As with other cell types, it’s caused by exposure to asbestos.
Cell Description and Behavior:
- Consists of epithelioid and sarcomatoid cells
- More epithelioid cells corresponds to more epithelioid behavior
- More sarcomatoid cells corresponds to more sarcomatoid behavior
The survival time for most patients with biphasic mesothelioma hovers around 12 months. But many live much longer. This depends on the ratio of epithelioid to sarcomatoid cells. Having more epithelioid cancer cells in the tumor is a good thing. It may affect your prognosis by only a few months or maybe a few years.
It can be difficult to diagnose biphasic mesothelioma. Biopsy samples usually only take a small piece of the tumor. The epithelioid and sarcomatoid cells may be close together or far apart on a biopsy sample. Pathologists may miss the biphasic aspect of the condition if they only see one cell type under the microscope.
It may take a larger sample of the tumor to identify biphasic mesothelioma. And some people only find out they have biphasic disease after surgery.
Biphasic cell type treatment involves surgery, chemotherapy and radiation. The stage of the disease often determines treatment. For example, stage 4 biphasic mesothelioma is considered inoperable. Stage 4 patients can expect non-surgical treatments, but it’s rare that only one type of therapy is used.
Many patients have two or three types of treatment, depending on the location of the tumor and response to therapy.
Treating Your Cell Type
Surgery is the best way to improve your life expectancy. However, surgery isn’t an option for every patient. This is partly due to cell types. Of course, there are other factors doctors must take into account.
Mesothelioma stage is one of the main factors used by doctors when considering surgery. Stage shows how far your disease has spread. Most surgeons consider patients with stage 1, 2 and 3 to be potentially operable. But your cell type is often a more important factor when surgeons determine if they can operate.
“Resectability” is the likelihood that the surgeon can remove most of the mesothelioma tumors. Surgeons always must consider the resectability of your mesothelioma.
According to the American Cancer Society, “Whether or not the cancer can be removed depends not only on how far the tumor has grown, but also on its subtype (most doctors believe only epithelioid and mixed/biphasic tumors are potentially resectable), where it is located, and if the patient is healthy enough to have surgery.”
Patients with epithelioid mesothelioma have a better chance of being eligible for surgery. This is because their cell type spreads more slowly than sarcomatoid mesothelioma. But surgery may still be an option if you have sarcomatoid mesothelioma. It depends partly on the resectability of your disease and your overall health status.
Here are some other important health factors that make a patient more eligible for surgical treatment:
- Good overall health
- Ability to continue daily life normally
- Younger age
- No chest pain
- Little weight loss
- Normal red and white blood cell counts
- Normal blood platelet counts
Finding Treatment for Your Cell Type
Most mesothelioma specialists have experience treating all cell types. If you were diagnosed with epithelioid mesothelioma (or a predominantly epithelioid mixed type), surgery is likely your best treatment option. Those with sarcomatoid mesothelioma may have to look for alternative treatments. Chemotherapy, radiation and experimental therapies are used to treat sarcomatoid mesothelioma.
Things remember about cell type:
- Your cell type greatly determines life expectancy.
- Epithelioid mesothelioma is the most treatable.
- There are treatments for all cell types.
No matter your diagnosis, there is a specialist who is right for you. Choosing your specialist is one of the most important ways to take control of your situation. Find out more about getting treated by a specialist.