LAUSR

ABSTRACT Background: Mesothelioma of peritoneal origin has wider variation in treatment outcomes than mesothelioma of pleural origin, likely because peritoneal mesothelioma comprises borderline malignant variants and aggressive malignant peritoneal mesothelioma (MPeM). This study retrospectively evaluates the efficacy of first-line systemic pemetrexed and cisplatin chemotherapy in MPeM. Research design and methods: Twenty-four patients with histologically proven MPeM were treated with pemetrexed plus cisplatin as a first-line systemic chemotherapy. The response was evaluated radiologically according to standard Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Twenty-two patients underwent 18F-fluorodeoxyglucose positron emission tomography/(FDG-PET)/computed tomography(CT) at baseline, and 13 were eligible for metabolic assessment. Results: Two complete responses and 9 partial responses were achieved. Overall response rate and disease control rate were 45.8% and 91.7%, respectively. Median progression-free survival and median overall survival were 11.0 months and 15.8 months, respectively. Wet- type MPeM had significantly longer survival (40.9 months median) than other clinical types (15.5 months) (P = 0.045). The baseline maximum standardized uptake value in 22 patients was 8.93 (range, 2.5–16.77). Conclusions: Systemic pemetrexed plus cisplatin is active for MPeM. Disparity with the outcome of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) needs to receive more emphasis, since peritoneal mesothelioma has a 5-year survival rate of 50%.