Definition
- A rare, aggressive cancer arising from the mesothelial lining of pleura (most common), peritoneum, pericardium, or tunica vaginalis.
- Strongly linked to asbestos exposure (latency 20–50 years).
Epidemiology & Risk Factors
- >80% cases are pleural.
- Median age at diagnosis: ~70 years.
- Male predominance (occupational exposure).
- Risk factors:
Pathology / Subtypes
- Epithelioid (~60%) → best prognosis
- Sarcomatoid (~20%) → worst prognosis
- Biphasic (mixed) (~20%) → intermediate
Clinical Presentation
- Progressive dyspnea
- Non-pleuritic chest pain
- Pleural effusion
- Cough, weight loss, fatigue
Diagnosis
- Imaging: Chest CT (pleural thickening, effusion, nodularity)
- Biopsy: VATS (video-assisted thoracoscopic surgery) preferred
- Immunohistochemistry: Positive for calretinin, WT-1, CK5/6 (helps distinguish from adenocarcinoma)
- Staging: AJCC TNM system
Treatment
Depends on stage, performance status, and histology.
1. Surgery (selected patients, early disease, epithelioid)
- Extrapleural pneumonectomy (EPP)
- Pleurectomy/decortication (P/D)
2. Chemotherapy (systemic)
- First-line standard (unresectable disease):
- Cisplatin + Pemetrexed (± Bevacizumab, if eligible)
- Alternative: Carboplatin + Pemetrexed (less toxic, older patients)
- Nivolumab + Ipilimumab (CheckMate-743 trial) → FDA-approved as first-line for unresectable mesothelioma (especially non-epithelioid).
4. Radiation
- Palliative (pain, effusion, chest wall invasion).
5. Supportive Care
- Pleural effusion management (pleurodesis, tunneled catheter).
- Analgesia, symptom control.
Prognosis
- Median survival: 9–18 months (depends on stage and subtype).
- Better: epithelioid, early stage, good performance status.
- Worse: sarcomatoid, advanced disease.
Key Pharmacist Point:
- Cisplatin + Pemetrexed is the chemotherapy backbone.
- Nivolumab + Ipilimumab is now an alternative first-line standard.
- Supplement folic acid and vitamin B12 with pemetrexed to reduce myelosuppression and GI toxicity.