Malignant Epithelioid Mesothelioma

What Is Epithelial Mesothelioma?

Epithelial mesothelioma is the most common of the three cell types of mesothelioma cancer. This tumor cell type involves cuboid cells with low mobility that group together and have visible nuclei. Epithelial and epithelioid both refer to this type of asbestos-related cancer.

More than 50% and up to 70% of mesothelioma cases are epithelioid. Epithelial cells line the portion of the airway known as the bronchus, an area susceptible to asbestos inhalation. The respiratory tract lining consists of pseudostratified columnar ciliated epithelium, which serves as a protective barrier. 

Patients with this tumor cell type live about six months longer than patients with other cancer cell types. It has the best prognosis of the three mesothelioma cell types because it is the most responsive to treatment. Due to this higher response rate, epithelioid cases tend to qualify for more aggressive and effective treatment plans.

Mesothelioma tumor location has a more significant impact than cell type on the kind of treatments a patient will undergo. However, cell types such as epithelial sarcomatoid or biphasic affect whether patients qualify for specific aggressive therapies.

Characteristics of Epithelial Cells

Epithelial mesothelioma cells clump together in groups. Each cell is square, cubed, columnar (long) or squamous (flat) in appearance. The nucleus, the central cellular region that contains genetic material, is noticeably visible in each cell.

Because epithelioid cells lack mobility and adhere closely together, they are less likely to spread and metastasize than sarcomatoid cells. This characteristic is one of the reasons epithelial mesothelioma has a better prognosis than other cell types.

Symptoms of Epithelial Cell Mesothelioma

Mesothelioma symptoms remain the same regardless of the cells that make up tumors. Tumor cell types primarily impact treatment response and growth rate, but they do not influence symptoms. Epithelioid tumor cells do not cause symptoms different from other cell types.As cancer grows and spreads, symptoms appear when organs such as the lungs, heart or kidneys are affected. Initial symptoms of pleural or peritoneal mesothelioma include cough, shortness of breath and lack of appetite. As the disease progresses, more severe symptoms may surface.

Prognosis for Epithelial Mesothelioma

According to data published in 2018 from the National Mesothelioma Virtual Bank, the median survival of epithelioid patients is 18 months. This life expectancy measures the time from diagnosis until death. Patients with biphasic cell type have a median survival of 10 months, and life expectancy is seven months for people with sarcomatoid cells.

Compared with other cell types, patients with epithelioid cells had an improved prognosis of around 200 additional days of survival. This enhanced survival rate can add years to a patient’s life expectancy if they receive an early-stage diagnosis with aggressive treatment.

According to a 2020 study published in Oncology Reports, epithelioid mesothelioma prognosis depends on a protein called CTGF, or connective tissue growth factor. Patients with lower levels of this protein had a better prognosis and more prolonged survival.

Epithelial cell type allows patients to access more aggressive treatment plans, such as surgery, and innovative clinical trials, especially when treated at a mesothelioma specialty clinic.

“Epithelial cell type by far is the best malignant mesothelioma cell type to have. This patient will definitely have more options such as surgery and is more likely to respond to treatment. The survival rate for epithelial patients is overall significantly longer.”

Karen Selby, R.N.

Patient Advocate

Epithelial Mesothelioma Diagnosis

Accurately diagnosing epithelioid mesothelioma requires multiple steps. Many patients experience significant delays between the onset of symptoms and receiving an accurate diagnosis.

When symptoms first appear, such as cough or shortness of breath, they can be vague and prompt general practitioners to order several tests to rule out other illnesses. Eventually, after radiology exams and a biopsy procedure, a mesothelioma specialist can confirm a diagnosis with a tumor cell type.

Challenges

Several obstacles may delay your physician from obtaining a tissue sample. Mesothelioma patients wait approximately three months after symptoms appear before they receive a diagnosis. 

Only a tumor biopsy, collected through a procedure such as a thoracoscopy or fine-needle aspiration, leads to accurate identification of epithelioid mesothelioma.

One of the most important things you can do to minimize diagnostic delays is to share any history of asbestos exposure with your health care provider.

If your doctor knows you have a history of asbestos exposure, they are more likely to consider mesothelioma or another asbestos-related condition.

Role of Immunotherapy in Diagnosis

Immunohistochemistry is a laboratory test to detect proteins on the surface of cells. These proteins help classify cancer cell types.

Pathologists use immunohistochemistry to identify epithelioid mesothelioma and differentiate it from another type of cancer called adenocarcinoma.

According to the 2018 ASCO pleural mesothelioma treatment guidelines, immunohistochemistry is the recommended test for suspected mesothelioma tumors.

This analysis will confirm the absence or presence of mesothelioma cell markers, leading to the most accurate diagnosis possible.

Your pathology results will show the specific cell type of your cancer. If you don’t have a record of your cell type, be sure to ask your doctor and request a copy of the pathology report for your records.

Epithelial Mesothelioma Cell Subtypes

When a pathologist outlines their report for your treating physician, they provide a wide breadth of information. 

These details include the biopsy site where the sample originated, how the surgeon collected the sample, cell characteristics, the distribution of cells in the tissue and an overall diagnosis. 

Epithelial cells can vary in many different ways, leading to several additional cellular subtypes within this group. These subtypes can inform your doctor how your cancer might progress and which treatments may be most appropriate.

Epithelial Mesothelioma Treatment Options

Patients have a better chance of improving life expectancy when they seek out specialized mesothelioma care and treatments tailored to their diagnosis. The first step in finding the best mesothelioma treatment is to seek the advice of an expert physician.

Of the three mesothelioma types, epithelial responds best to treatment. Patients diagnosed with the epithelial variant tend to have more treatment and clinical trial options, such as immunotherapy and radiation therapy. 

Early-stage epithelioid mesothelioma is treated aggressively with a combination of surgery, chemotherapy and radiation therapy. According to a 2019 report in The Annals of Thoracic Surgery, combination therapy resulted in significantly better outcomes for patients with epithelial malignant pleural mesothelioma.

As cancer progresses it has a higher chance of spreading and metastasizing to other areas, making surgery less beneficial. Late-stage cases respond better to chemotherapy, immunotherapy and Tumor Treating Fields therapy.

Common Questions About Epithelial Mesothelioma

How does a mesothelioma cell type affect my prognosis and treatment?

Patients with the epithelioid cell type have the most mesothelioma treatment options because their cell type responds the best to all forms of treatment. Epithelioid patients also live an average of 200 days longer than patients with other cell types.

How do I find a doctor who treats epithelial mesothelioma?

Most oncologists are not trained to treat epithelioid mesothelioma. Mesothelioma doctors have trained for years to specialize in the treatment of this cancer. Our Patient Advocates can help you find a top doctor who treats epithelial mesothelioma.