ASO Author Reflections: Management of Malignant Peritoneal Mesothelioma
Malignant peritoneal mesothelioma (MPM) is an uncommon subtype of mesothelioma, less often related to asbestos exposure and more often occurring in younger patients.1 Owing to its rarity, MPM remains largely understudied, with extremely limited prospective randomized data. The historical standard of care for MPM includes systemic chemotherapy, but response rates are poor.2 As a result, alternative monotherapies and combinatorial strategies have been explored, including cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), normothermic early postoperative chemotherapy (EPIC), and sequential chemotherapy (SIC).3, 4, 5 Our National Cancer Data Base study sought to evaluate management patterns, outcomes, and prognostic factors of MPM using a large, contemporary national database.6
In our article, we reported that the most common treatment approach was observation alone (25%), followed by chemotherapy only, CRS alone, CRS with chemotherapy, and CRS/HIPEC.6 There were no temporal differences in treatment use between 2004 and 2013. Younger age, female sex, insurance status, residence in higher educated areas, living farther from treating institutions, and treatment at academic centers were all predictive of undergoing CRS. Patients with sarcomatoid and biphasic histologies were less likely to undergo CRS compared with those with epithelioid histology. CRS appears to be safe, with low postoperative mortality rates. Although this retrospective analysis cannot imply causation, patients who underwent combined chemotherapy and CRS had numerically improved overall survival versus any monotherapy, while those who were observed had the lowest overall survival.
Despite controlling for and minimizing biases in this retrospective study, our results must be interpreted with caution. While it is clear that MPM treatment strategies are influenced by a variety of factors, including age, sociodemographics, geography, and histology, prospective studies are needed to compare efficacy of treatment strategies. Future studies should also evaluate for differences between histologies. To overcome poor accrual, prospective trials of MPM will likely necessitate national or multinational collaborations.
Taylor R. Cushman, Vivek Verma, and Charles B. Simone II have no conflicts of interest to disclose.