Current Management and Future Opportunities for Peritoneal Metastases: Peritoneal Mesothelioma

Diffuse malignant peritoneal mesothelioma (MPM) is a rare and ultimately fatal cancer that was first described just over a century ago. It is a diffuse malignancy arising from the mesothelial lining of the peritoneum; morbidity and mortality from MPM is due to its propensity to progress locoregionally within the abdominal cavity. The purpose of this article is to review the current state-of-the-science related to the diagnosis, staging, and treatment of MPM. The condition afflicts men and women equally and the peak incidence is between 55 and 60 years of age although it can arise in the young and elderly. Patients afflicted with MPM most commonly present with nonspecific abdominal symptoms that usually lead to diagnosis when the condition is relatively advanced. Historically, median overall survival for MPM patients without treatment is < 1 year. The couplet of systemic pemetrexed and cisplatin has an overall response rate of approximately 25% and a median overall survival of approximately 1 year. The available data, almost all retrospective in nature, have shown that in selected patients, operative cytoreduction (CRS) and regional chemotherapy administered as hyperthermic intraoperative peritoneal chemotherapy (HIPEC) or early postoperative intraperitoneal chemotherapy (EPIC) is associated with long-term survival. Studies on the molecular biology of MPM have yielded new insights relating to the potentially important role of the phosphoinsitide-3-kinase/mammalian target of rapamycin (PI3 K/mTOR) pathways and immune checkpoint inhibitors that may translate into new therapeutic options for patients with diffuse MPM.