Epithelioid Mesothelioma: Causes, Diagnosis, and Evidence-Based Treatment

Epithelioid mesothelioma, the most prevalent subtype of mesothelioma, accounts for 50–70% of all cases. Linked almost exclusively to asbestos exposure, this cancer arises in the mesothelial cells lining organs like the lungs (pleura) or abdomen (peritoneum). With a better prognosis than sarcomatoid or biphasic subtypes, understanding its scientific foundations is critical for patients and caregivers. This guide explores epithelioid mesothelioma through a fact-based lens, focusing on U.S.-centric data, proven treatments, and emerging research.

What Is Epithelioid Mesothelioma?

Subtype Characteristics

Epithelioid mesothelioma is defined by its epithelial-like cell structure, which resembles healthy mesothelial cells under a microscope. This subtype grows slower and responds better to treatment than other forms, contributing to a median survival of 12–24 months with therapy (National Cancer Institute).

Key Statistics

Incidence: 3,000+ new mesothelioma cases are diagnosed annually in the U.S., with epithelioid comprising 50–70% (American Cancer Society).
Latency Period: 20–50 years between asbestos exposure and symptom onset.
Demographics: Primarily affects males over 65 due to occupational asbestos exposure.

Also Read: The Importance of Hiring Professional Asbestos Removal Firms

Causes and Risk Factors

Asbestos Exposure

The U.S. Environmental Protection Agency (EPA) confirms asbestos as the sole proven cause of mesothelioma. When inhaled, asbestos fibers lodge in the mesothelium, causing chronic inflammation, DNA damage, and malignant cell growth. High-risk occupations include:

Construction workers
Shipyard employees
Automotive mechanics (handling asbestos-containing brakes)

Genetic and Biomarker Insights

BAP1 Mutations: Found in 60% of mesothelioma cases, this tumor-suppressor gene mutation increases susceptibility (NIH Study, 2020).
Mesothelin: A protein overexpressed in epithelioid cells, used as a diagnostic biomarker.

Symptoms and Diagnosis

Common Symptoms

Pleural: Chest pain, shortness of breath, pleural effusion.
Peritoneal: Abdominal swelling, nausea, unexplained weight loss.

Diagnostic Methods

Imaging:
- CT Scans: Identify tumors and fluid buildup.
- PET Scans: Detect metastasis.
Biopsies:
- Thoracoscopy: For pleural cases.
- Laparoscopy: For peritoneal cases.
Immunohistochemistry: Distinguishes epithelioid mesothelioma from lung adenocarcinoma using markers like calretinin and WT-1.

Also Read: Neo Guide to Mesothelioma: Modern Insights into Causes, Diagnosis, and Treatment

Evidence-Based Treatment Options

Surgery

Pleurectomy/Decortication (P/D): Removes tumors while preserving the lung (preferred for early-stage patients).
Cytoreductive Surgery (CRS): For peritoneal cases, often paired with HIPEC (heated intraperitoneal chemotherapy), yielding 5-year survival rates up to 50% in select patients (Annals of Surgical Oncology).

Chemotherapy

Pemetrexed + Cisplatin: FDA-approved first-line regimen with a 40% response rate (New England Journal of Medicine).

Radiation

Intensity-Modulated Radiation Therapy (IMRT): Minimizes damage to healthy tissues.

Immunotherapy

Checkpoint Inhibitors: Nivolumab (Opdivo) and ipilimumab (Yervoy) show a 40% 2-year survival rate in clinical trials (Journal of Clinical Oncology).

Clinical Trials

CAR T-Cell Therapy: Targets mesothelin in early-phase trials.
TTFields (Tumor Treating Fields): Disrupts cell division using electric fields.

Prognosis and Survival Rates

Factors Influencing Outcomes

Stage at Diagnosis: Early-stage (I/II) patients survive 18–24 months vs. 8–12 months for advanced stages.
Cell Type: Pure epithelioid has a median survival of 19 months vs. 8 months for sarcomatoid (NIH SEER Database).

Survival Statistics

1-Year Survival: 73% for epithelioid vs. 23% for sarcomatoid.
5-Year Survival: 10–15% with aggressive multimodal therapy.

Patient Resources and Support

Specialized Treatment Centers

MD Anderson Cancer Center (TX): Leader in HIPEC and immunotherapy.
Brigham and Women’s Hospital (MA): Pioneers in mesothelioma research.

Also Read: Leonard Bernstein: A Musical Genius and His Battle with Mesothelioma

Financial Assistance

Asbestos Trust Funds: Over $30 billion available for U.S. victims.
VA Benefits: Veterans receive monthly compensation for service-related exposure.

Advocacy Organizations

Mesothelioma Applied Research Foundation (MARF): Offers clinical trial matching and counseling.

This blog is for informational purposes only. Treatment outcomes vary based on individual health factors. Always consult a board-certified oncologist or sources like the National Cancer Institute (NCI) for personalized medical advice. By focusing on scientifically validated data and U.S.-centric resources, this guide empowers patients to navigate epithelioid mesothelioma with informed clarity. Early diagnosis and access to specialized care remain pivotal in improving outcomes. Stay updated on advancements through reputable organizations and clinical trials.