Evaluation of combined cyclophosphamide and methotrexate therapy in the treatment of metastatic carcinoid tumor and the malignant carcinoid syndrome.

Sixteen patients with metastatic carcinoid tumor and the malignant carcinoid syndrome were treated with combined cyclophosphamide and methotrexate therapy in a regimen previously described as highly effective. Toxicity was relatively mild and consisted primarily of leukopenia. One patient experienced some symptomatic benefit and minor reduction in hepatomegaly and 5-hydroxyindoleacetic acid excretion. None met our criteria for an objective response. Combined cyclophosphamide and methotrexate therapy does not appear to offer significant benefit for this disease.