What Is Sarcomatoid Mesothelioma?

Sarcomatoid mesothelioma is a rare form of cancer caused by asbestos. This cancer can affect the lungs, heart, abdomen or testes. Sarcomatoid refers to the tumor cell type. These cells make up most of the tumors for this type of mesothelioma.

Sarcomatoid cell mesothelioma stain
A pathology stain showing sarcomatoid mesothelioma cells under a microscope.

This form of mesothelioma cancer is more resistant to treatment than epithelial or biphasic cell types. Sarcomatoid tumor cells are more likely to spread to new areas. This cell type is present in pleural mesothelioma cancer 98% of the time. About 2% of peritoneal mesothelioma patients have the sarcomatoid type.

Sarcomatoid mesothelioma accounts for 10% to 20% of all mesothelioma cases. Doctors diagnose 300 to 600 new patients with this cell type yearly. It is the rarest of the three primary cell types. For comparison, about 60% of patients have the epithelial type, and 20% have the biphasic type.

What Causes Sarcomatoid Mesothelioma?

Asbestos is the primary cause of sarcomatoid mesothelioma. Breathing or swallowing asbestos traps fibers in the body. Over time, irritation and inflammation lead to mesothelioma cancer. Mesothelioma risk factors include exposure on the job or from the environment. 

Symptoms take a long time to appear, approximately 20 to 60 years after asbestos exposure. They often resemble those of more common illnesses. If you have a history of asbestos exposure, speak with your doctor about early screening. The earlier your doctor can identify this cancer, the more treatment options may be available to you.

What Are the Symptoms of Sarcomatoid Mesothelioma?

Sarcomatoid cells most often appear in the pleura, the lining of the lungs. The mesothelioma symptoms for this cell type, such as cough and shortness of breath, tend to involve the respiratory system.

Common symptoms of sarcomatoid mesothelioma include:
  • Anemia (low iron)
  • Chest pain or abdominal fullness
  • Coughing up blood
  • Fatigue and extreme tiredness
  • Lack of appetite, anorexia and nausea
  • Low blood oxygen levels
  • Persistent cough
  • Prolonged hoarseness
  • Shortness of breath
  • Weight loss and weakness

Patients with sarcomatoid peritoneal cancer will have abdominal symptoms. They may experience bowel problems, abdominal pain and swelling. As the disease progresses, symptoms become more serious. If you have these signs and a history of asbestos exposure, speak with a specialist as soon as possible.

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How Is Sarcomatoid Mesothelioma Diagnosed?

Doctors use imaging and biopsies to confirm a sarcomatoid mesothelioma diagnosis. Imaging studies such as X-rays, CT scans and MRIs reveal abnormalities in the chest. Your doctor or a surgeon will collect a tissue sample for the biopsy. Another doctor reviews the cells under a microscope and creates a pathology report.

Only a biopsy can show specific details such as cell type. Sarcomatoid cells are long, narrow and shaped like spindles. Epithelial cells are round and rectangular, making them easier to treat.

The shape of sarcomatoid cells causes them to break apart more often. As they do, the cells become more challenging to remove, and can travel to new areas and metastasize. 

Understanding Your Pathology Report

Your pathology report includes a wealth of information about your cancer. It describes the tumor cell type, biomarkers and cancer stage. Your doctor uses the findings to complete your diagnosis or alongside blood tests to track treatment. These details also help you understand your diagnosis. Ask your doctor about your report so you can make informed treatment decisions.

Immunohistochemical markers, or biomarkers, can indicate how to treat your cancer. These markers are like flags telling your doctor which drugs work best. For example, if sarcomatoid cells in your tumor express high levels of PD-L1, it will appear when a pathologist stains them. In this case, checkpoint inhibitor drugs such as Opdivo and Yervoy may be the most effective.

Rare Sarcomatoid Cell Types

Rare sarcomatoid mesothelioma cell subtypes can complicate your diagnosis. These rare types come in three categories. Some may provide a better prognosis. Others can point to a higher chance of metastasis.

  • Desmoplastic Mesothelioma. This sarcomatoid subtype is one of the most difficult to diagnose. With this cell type, doctors may be unable to track if your tumor is growing.
  • Lymphohistiocytoid Mesothelioma. These tumors contain inflammatory and immune cells. This can translate to more symptoms but also a better life expectancy.
  • Transitional Mesothelioma. This type grows and spreads like other subtypes. It consists of large, spindle-shaped cells that make it easier to diagnose.

Sarcomatoid mesothelioma subtypes are rare. They most often develop in the pleura. Ask your physician whether there are any abnormalities in your pathology report. They can offer more information on your prognosis.

What Is The Survival Rate of Sarcomatoid Mesothelioma?

The median overall survival for sarcomatoid mesothelioma is 8.6 months. In a 2021 clinical research study, patients with sarcomatoid mesothelioma who received immunotherapy had a median overall survival of 15 months. The median overall survival was 10.7 months for those who received chemotherapy.

Each patient’s prognosis differs based on health, tumor location and metastasis. Doctors use past data to make prognosis estimates. Patients with pleural sarcomatoid mesothelioma survive about five months. Those with the peritoneal form have a life expectancy of about 10 to 11 months after diagnosis. Women with the sarcomatoid type tend to live longer than men. 

Sarcomatoid cells are resistant to treatment because of their fibrous nature. Your outlook will improve as more treatment options become available. New therapies through clinical trials may work better for some patients.

“The most impressive advancement for checkpoint blockade has been the demonstration that for people with sarcomatoid and biphasic mesothelioma, we can double survival with the combination of ipilimumab and nivolumab,” Dr. Anna Nowak, a researcher at the Institute for Respiratory Health in Western Australia, told The Mesothelioma Center at Asbestos.com.

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How Is Sarcomatoid Mesothelioma Treated?

Sarcomatoid mesothelioma treatment options include immunotherapy, chemotherapy, targeted therapy and radiation therapy. These options differ for each patient based on cancer stage, tumor extent and overall health. Seeking a mesothelioma specialist at a top cancer center is the best way to learn all your options. 

There is currently no cure for sarcomatoid or any other variant of mesothelioma. Treatments can improve symptoms, extend survival and increase the quality of life. Surgery is less beneficial for sarcomatoid patients because recurrence is more likely.

“Sarcomatoid mesothelioma is a little less responsive to chemotherapy,” mesothelioma specialist Dr. Andrea Wolf of Mount Sinai Hospital told The Mesothelioma Center at Asbestos.com. “But from what we see from more recent data, it may be more responsive to immunotherapy. And we have additional treatment options for those patients.”

Chemotherapy

Pemetrexed (Alimta) plus cisplatin or carboplatin is the standard chemo regimen. It is best for patients who have had no prior cancer therapy. Doctors use these drugs in a first-line setting for any cell type. Patients treated with first-line chemotherapy have a median survival of 15 months. Side effects are often nausea and fatigue. 

Immunotherapy

The U.S. Food and Drug Administration has approved the immunotherapy drugs nivolumab and ipilimumab. They are effective for sarcomatoid mesothelioma. The combo can improve patient survival by four months compared to chemotherapy. The drugs are also known by their brand names, Opdivo and Yervoy. Side effects include rash, nausea and fatigue. 

Radiation Therapy

Doctors use radiation alongside other therapies in a multimodal plan. Radiation therapy is not considered curative for mesothelioma. It has increased 2-year life expectancy by 30% for some patients. It can also reduce pain and improve the quality of life. Side effects include rash, cough and fatigue. 

Emerging Therapy

Targeted therapies treat cancer without harmful effects on the rest of the body. AZD8186 is a targeted therapy drug showing effectiveness for some cancers in clinical trials. Another example is Tumor Treating Fields. This therapy is noninvasive. It uses adhesive pads and electrical pulses to disrupt tumor growth. 

Palliative Care

Doctors use less invasive forms of therapy, such as chemotherapy and surgery, to ease symptoms. This method is known as palliative care. Surgery is less effective for sarcomatoid patients, yet tumor removal can improve breathing quality. Low-dose chemo and radiation can also slow growth. This method allows more time with fewer symptoms before the end of life.

Common Questions About Sarcomatoid Mesothelioma

Where can I get treatment for sarcomatoid cell mesothelioma?

You may get treatment for sarcomatoid mesothelioma from a specialist at a top treatment center. This cell type is more challenging to treat and requires a team of experts. If you have pleural cancer, you need the best thoracic surgeons and oncologists with asbestos-related cancer experience. For peritoneal patients, seeks top doctors with years of experience in asbestos cancers and abdominal cancer treatment.

Can sarcomatoid mesothelioma be prevented?

You can prevent sarcomatoid mesothelioma by being aware of asbestos exposure risks. Exposure tends to happen at job sites or from damaged materials containing asbestos. Find out whether you have asbestos-containing materials in your home. If you do, take steps to prevent exposure, such as hiring an abatement professional.

Is sarcomatoid mesothelioma curable?

Like other forms of this cancer, sarcomatoid mesothelioma is not curable. Clinical research trials are testing the latest methods to improve the safety and effectiveness of new drugs. Talk to your doctor about the best options for you. Some treatments, such as those in clinical trials, may extend your life for several years.

Is there any ongoing research on sarcomatoid mesothelioma?

Yes, researchers are working on novel ways to treat sarcomatoid mesothelioma. Many patients have found success with new immunotherapy drugs. You may be eligible to join a clinical trial and receive the latest medication that targets sarcomatoid cells. Ask your mesothelioma specialist which treatments are right for you.

Is sarcomatoid mesothelioma different than sarcomatoid carcinoma?

Yes, sarcomatoid mesothelioma and carcinoma are two different types of cancer with unique origins and characteristics. Sarcomatoid mesothelioma is a subtype of malignant mesothelioma. This cancer arises from the mesothelial cells that line the lungs, abdomen or heart. It involves the presence of spindle-shaped or elongated tumor cells. These cells resemble those in sarcoma, a cancer that arises from connective tissue.

Sarcomatoid carcinoma is a subtype of carcinoma. This cancer comes from epithelial cells that line various organs and tissues. It can occur in several organs, including the lungs, liver and pancreas. Treatment is often different between the two types based on location and stage.