Malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPeM) is a rare and aggressive cancer that arises from the mesothelial cells lining the peritoneum, the thin membrane that covers the abdominal cavity and its organs. It accounts for approximately 10–30% of all mesothelioma cases, with the majority of mesotheliomas occurring in the pleura (lining of the lungs). The disease primarily affects the abdominal cavity and can spread to involve the omentum, intestinal surfaces, liver capsule, and other abdominal organs. The strongest known risk factor is prior exposure to asbestos, although a significant proportion of patients — particularly women — have no identifiable asbestos exposure history, suggesting other environmental or genetic factors may play a role. Key symptoms of malignant peritoneal mesothelioma include progressive abdominal distension due to ascites (fluid accumulation in the abdomen), abdominal pain, weight loss, loss of appetite, nausea, and bowel changes. As the disease progresses, patients may develop intestinal obstruction and palpable abdominal masses. Diagnosis is often delayed because symptoms are nonspecific and can mimic many other abdominal conditions. Definitive diagnosis requires tissue biopsy with immunohistochemical staining to distinguish mesothelioma from other peritoneal malignancies such as peritoneal carcinomatosis or primary peritoneal serous carcinoma. The current treatment landscape has evolved significantly. The standard of care for eligible patients is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC), which has substantially improved survival outcomes compared to systemic chemotherapy alone. Systemic chemotherapy, typically a combination of pemetrexed and cisplatin or carboplatin, is used for patients who are not surgical candidates or who have recurrent disease. More recently, immune checkpoint inhibitors (such as nivolumab and ipilimumab) have shown promise and have been approved for unresectable mesothelioma. Despite advances, prognosis remains guarded, though outcomes are generally better than for pleural mesothelioma, with median survival ranging from 1 to 5 years depending on disease stage and treatment approach.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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