50 Patients with Malignant Mesothelioma of Both the Pleura and Peritoneum: A Single-Institution Experience.

Background: The most common sites of malignant mesothelioma are the pleura and peritoneum, but little is known about the incidence, prognosis, or treatment of patients with disease in both cavities. Previous series suggest that multimodality treatment improves overall survival for pleural or peritoneal disease, but studies typically exclude patients with disease in both cavities. Despite limitations, this investigation is the only study to broadly examine outcomes for patients with malignant mesothelioma in both the pleural and peritoneal cavities.

Methods: This study retrospectively examined 50 patients with both pleural and peritoneal mesothelioma treated with the intent to prolong survival. The primary end point was overall survival from the initial operative intervention.

Results: The median overall survival was 33.9 months from the initial intervention. Female gender and intraperitoneal dwell chemotherapy were independent predictors of overall survival. Within 1 year after the initial diagnosis, second-cavity disease was diagnosed in 52% of the patients. The median time to the second-cavity diagnosis for those with a diagnosis 1 year after the initial diagnosis was 30 months.

Conclusions: Well-selected patients with both pleural and peritoneal mesothelioma have a survival benefit over palliative treatment that is comparable with that seen in single-cavity disease. The presence of disease in both cavities is not a contraindication to multimodality treatment aimed at prolonging survival, whether the disease is diagnosed synchronously or metachronously. Patients with an initial diagnosis of single cavity disease are at the highest risk for identification of second-cavity disease within the first year after diagnosis.