Chemotherapy in malignant pleural mesothelioma. A review

We reviewed the published literature of clinical studies in malignant pleural mesothelioma, including phase II trials of the newer antifolates and plant derivatives, as well as older single-agent and combination chemotherapy trials. We excluded trials with less than 15 patients, although we have mentioned smaller trials in the text to make a specific point, as well as ones that show promise. We have also included confidence intervals when cited in the original reports, or calculated them when absent.

No drugs have consistently induced a response greater than 20%. Higher response rates have been reported with detorubicin, high-dose methotrexate, and edatrexate at 26%, 37%, and 25%, respectively, but these have yet to be confirmed. Agents that produce response rates in 10% to 20% of patients include doxorubicin, epirubicin, mitomycin, cyclophosphamide, ifosfamide, cisplatin, and carboplatin. Combination chemotherapy trials do not demonstrate a consistently greater response rate than single-agent trials. However, the combination of doxorubicin, cisplatin, bleomycin, and mitomycin demonstrated a response rate of 44% (95% confidence interval, 27% to 63%), but this remains unconfirmed. Intrapleural therapy using interferon gamma, particularly for small-volume disease, shows promise.

The successful treatment of unresectable pleural mesothelioma awaits the discovery of active drugs. Recent trials of high-dose methotrexate and other antifolates are encouraging. Newer agents, including suramin, should be evaluated in phase II trials. Off-protocol combination therapy cannot be recommended over single-agent therapy, but studies that use combinations of the newer agents should be conducted.