WEEKLY HIGH-DOSE CISPLATIN IN MALIGNANT PLEURAL MESOTHELIOMA

Background: Cisplatin at conventional doses has marginal activity in mesothelioma. A dose-response relation for cisplatin has been suggested in other tumor types. In a phase I study on weekly cisplatin administration, 3 of 5 patients with mesothelioma responded. Therefore, a phase II study with weekly cisplatin was started with the recommended dose of 80 mg/m2/week for six weeks. Patients and methods: Fourteen patients with mesothelioma stage II, with measurable lesions, were treated with cisplatin at a dose of 80 mg/m2 weekly for six weeks. Cisplatin was administered in 3% NaCl and combined with ondansetron as antiemetic. Results: Five patients had partial responses (response rate 36%; 95% confidence interval 12%-65%) lasting 2-8 months. Seven patients had stable disease. Ototoxicity, grade 2 in 3 patients and grade 3 in 2, was the most troublesome side effect. Conclusions: Cisplatin given at a higher dose intensity than in conventional schedules is active in mesothelioma. The response duration is short, however, possibly due to lack of effective maintenance therapy.