Treatment of malignant mesothelioma with methotrexate and vinblastine, with or without platinum chemotherapy

To determine the efficacy of methotrexate, vinblastine, and platinum chemotherapy in patients with diffuse unresectable malignant mesothelioma.

Patients with histologically confirmed malignant mesothelioma were evaluated for treatment with methotrexate, vinblastine, and cisplatin chemotherapy. If the patient had preexisting hearing loss or neuropathy, or was significantly disabled (eg, spending greater than half of the day in bed or a chair), cisplatin therapy was withheld.

All patients were initially evaluated at the University of Washington Medical Center and received chemotherapy at the University of Washington or in the community.

Between 1990 and 1994, 17 patients received this chemotherapy. Ten patients received cisplatin, 100 mg/m2 IV on day 1, methotrexate, 30 mg/m2 IV on days 8, 15, and 22, and vinblastine, 3 mg/m2 IV on days 8, 15, and 22, in 28-day cycles. One patient had carboplatin substituted for cisplatin due to preexisting hearing loss. Six patients received weekly methotrexate and vinblastine at the same doses without platinum.

Nine of the 17 (53%; 95% confidence interval [CI], 28 to 77%) patients responded, including two complete remissions, two partial remissions, and five regressions. Median time to progression is 8 months. The median survival time for all patients is 14 months. Projected 2-year survival is 35% (95% CI, 12 to 60%).

Although the number of the patients in this study is small, the response rate and projected 2-year survival of 35% are better than those typically reported for unresectable malignant mesothelioma. Further investigation is warranted in confirmatory trials.