Types of Mesothelioma
There are four types of mesothelioma:
- Pleural mesothelioma forms in the lining of the lungs.
- Peritoneal mesothelioma develops in the lining of the abdomen.
- Pericardial mesothelioma forms in the lining of the heart.
- Testicular mesothelioma develops in the lining of the testicles.
Pleural and peritoneal mesothelioma are the two most common types and account for 98% of all cases. The pericardial and testicular types are extremely rare and account for approximately 1% of cases each.
Pleural mesothelioma is the most common form the disease, accounting for more than 75% of cases. Patients are typically diagnosed at a late stage of cancer development because the disease doesn’t cause symptoms until stage 3 or stage 4.
The prognosis for pleural mesothelioma is poor. Life expectancy is around one year with chemotherapy and 22 months with a combination of surgery, chemotherapy and radiation.
Peritoneal mesothelioma develops in the abdominal lining and accounts for approximately 20% of cases. The prognosis is around one year with chemotherapy. However, one-fifth of peritoneal patients are diagnosed early enough to qualify for cytoreductive surgery with heated chemotherapy, which helps half of the patients who receive it live longer than five years.
Mesothelioma is also classified by the type of cells that make up tumors.
Mesothelioma Cell Types
- Epithelioid Mesothelioma
Epithelioid mesothelioma is less aggressive than other cell types. It typically has a more positive prognosis compared with sarcomatoid and biphasic tumors.
- Sarcomatoid Mesothelioma
The sarcomatoid mesothelioma cell type is the least common form of the disease. Up to 20% of pleural mesothelioma diagnoses are the sarcomatoid tumor type. These cells are aggressive and more difficult to treat.
- Biphasic Mesothelioma
Biphasic mesothelioma is a mixture of epithelioid and sarcomatoid cells. In order to be classified as a mixed cancer, the tumor must contain at least 10% of each type of cell.
Symptoms of Mesothelioma Cancer
Symptoms of mesothelioma usually do not appear until stage 3 or stage 4 of the cancer.
- Shortness of breath
- Chest pain
- Trouble swallowing
- Weight loss
- Fever or night sweats
- Changes in bowel habits
- Abdominal pain and swelling
What Causes Malignant Mesothelioma?
Nearly all cases of mesothelioma are caused by asbestos exposure. The heavier the asbestos exposure and the longer a person is exposed throughout their lifetime, the higher the risk for mesothelioma.
Researchers estimate that 80% to 90% of all mesothelioma cases are directly related to asbestos. Most of this contact with asbestos has occurred in occupational settings.
There is a long latency period associated with mesothelioma and asbestos exposure. Most mesothelioma cases start to develop about 20 to 50 years after the exposure began. This latency period can make it difficult for patients to recall when and how they were exposed to asbestos.
Who Is Most at Risk of Asbestos Exposure?
Statistics for mesothelioma reveal about 3,000 people are diagnosed with a form of the cancer each year. The majority of mesothelioma patients have a history of working in an industry where contact with asbestos was common and frequent.
- Insulation workers
- Shipyard workers
- Construction workers
- Industrial workers
- Power plant workers
- Auto mechanics
- Chemical plant workers
- Boiler workers
U.S. military veterans are at risk of developing mesothelioma because the armed forces used asbestos on ships, automobiles and planes, and in shipyards, military bases and barracks.
Prognosis and Life Expectancy for Mesothelioma Patients
The prognosis for mesothelioma is poor because there is no cure, and the cancer is aggressive once it develops. However, some mesothelioma survivors have lived a long time despite the poor prognosis.
Most patients who undergo chemotherapy have a life expectancy of one year, and the five-year survival rate is around 10% for all cases of mesothelioma.
Survival is different among pleural and peritoneal patients who qualify for surgery. Surgical pleural patients live an average of 22 months. Surgical peritoneal patients have a 50% chance of living longer than five years.
Diagnosing Mesothelioma and Staging
Diagnosing mesothelioma is a complex process that involves biopsies to confirm what type of cancer cells are present. Imaging scans help determine the stage of the cancer.
Diagnosing mesothelioma may involve the following tests:
- Biopsies: A thoracoscopic biopsy is the most accurate test to confirm a mesothelioma diagnosis. Other biopsies may be used such as fine-needle aspiration, thoracentesis or mediastinoscopy.
- Blood Tests: While blood tests are not used to confirm a mesothelioma diagnosis, they are helpful at determining a patient’s overall health and response to treatment.
- Imaging Scans: X-rays, CT scans, PET scans and MRIs may be used to identify where tumors are located.
What Are the Stages of Mesothelioma?
The staging of mesothelioma is an important part of the diagnostic process because it guides treatment recommendations. For example, early-stage patients often qualify for surgery because the tumors are easier to remove.
Only pleural mesothelioma has an official staging system. A staging system is in development for peritoneal mesothelioma, but more data is required to make it official.
There are four stages of pleural mesothelioma:
- Stage 1
Mesothelioma cancer cells remain within the pleural lining.
- Stage 2
Cancer cells spread into lung tissue and nearby lymph nodes.
- Stage 3
Cancer cells spread into neighboring tissue such as the chest wall.
- Stage 4
By stage 4 mesothelioma, spreading continues throughout the chest cavity on both sides. In some cases, cancer cells spread into the abdominal lining or distant organs.
Mesothelioma Treatment Options
The mesothelioma treatment options your doctor recommends will depend upon the location of the cancer, the stage of progression, the tumor cell type and the patient’s overall health.
Because mesothelioma is so difficult to diagnose and treat, it is vital to see a mesothelioma doctor who has specialized in either pleural or peritoneal mesothelioma.
A mesothelioma specialist has the expertise to develop the best treatment plan for your case, and they work at cancer centers where the latest clinical trials and treatments are available.
Pleural Mesothelioma Treatment
The most common treatment for pleural mesothelioma is chemotherapy. A new therapy known as Tumor Treating Fields was approved by the U.S. Food and Drug Administration in 2019 to treat pleural mesothelioma.
Some patients who are diagnosed early qualify for a combination of surgery, chemotherapy and radiation therapy. This is known as multimodal treatment. Patients also turn to emerging treatments such as immunotherapy.
Peritoneal Mesothelioma Treatment
The vast majority of peritoneal mesothelioma patients undergo chemotherapy alone because they are diagnosed too late to qualify for the most effective treatment of cytoreductive surgery with heated chemotherapy.
- Chemotherapy Alone: The most common chemotherapy drugs used to treat peritoneal mesothelioma include cisplatin, Alimta (pemetrexed), gemcitabine and carboplatin.
- Surgery with Heated Chemotherapy: Cytoreductive surgery attempts to remove all visible mesothelioma tumors before the abdomen is washed in a heated chemotherapy bath. Half of all patients who receive the procedure live at least five years.
Radiation therapy is generally not used in peritoneal mesothelioma treatment because of the damage it can cause to internal organs.
Compensation for Patients and Loved Ones
It isn’t easy for most families to afford mesothelioma treatment. The financial burden of mesothelioma is often compared to treatment for lung cancer, which costs an estimated $60,000 for the first year, according to the National Cancer Institute.
Thankfully, most people with mesothelioma qualify for different forms of financial assistance.
People who develop mesothelioma may be eligible for compensation from the company or companies responsible for their asbestos exposure. Compensation from mesothelioma personal injury lawsuits and asbestos trust funds can help cover costs of treatment, travel expenses and loss of income.
To learn more about this option, you should consult a qualified mesothelioma lawyer. Working with an experienced attorney is your best chance at receiving the most compensation possible.
Patients and families coping with a mesothelioma diagnosis benefit from a strong system of support.
Finding resources and building a support team isn’t easy to do when you’re undergoing treatments or caring for a loved one with cancer. However, it is essential to moving forward in a positive way to reduce stress and get your family the help they need to thrive.
Many mesothelioma survivors credit the people who supported them along the journey as vital to their survival.
Common Questions about Mesothelioma
- What causes mesothelioma?
The primary cause of pleural mesothelioma is exposure to asbestos. Most people with mesothelioma were exposed to asbestos products through their occupation. Once inhaled, asbestos fibers can become stuck inside lung and abdominal tissue, causing damage over 20 to 50 years before mesothelioma begins to develop.
- How do I know if I have mesothelioma?
The only way to know if you have mesothelioma is to see a mesothelioma specialist for a biopsy. A biopsy is the only test that can confirm a mesothelioma diagnosis. Symptoms alone cannot be used to diagnose mesothelioma.
- How is mesothelioma treated?
The most common treatments for mesothelioma include surgery, chemotherapy, radiation therapy and Tumor Treating Fields. Some patients qualify for immunotherapy, while others try experimental therapies through clinical trials.
- What is the prognosis for mesothelioma?
The prognosis for mesothelioma is generally poor, but it depends upon the cell type and the stage at diagnosis. The average life expectancy is around one year. However, some patients are living longer thanks to early diagnosis and positive response to treatment.