Cytotoxic treatment in patients with malignant carcinoid tumors. Response to streptozocin--alone or in combination with 5-FU.

Thirty-one patients with malignant carcinoid tumors were treated with streptozocin--alone (n = 7) or in combination with FU (n = 24). The responses to treatment were followed by the determination of tumor markers, urinary 5-HIAA, serum PP, HCG-alpha and -beta subunits, as well as determination of the size of liver metastases on computerized tomography or ultrasonography. Three patients (9.7%) showed objective responses with a mean remission time of 2.7 months. Eighteen patients (58%) showed stable disease, whereas ten patients (32.3%) showed progressive disease directly from the start of therapy. A good correlation was found between the changes in tumor markers and tumor size, although the changes occurred earlier in the markers than in the size. Estimated median survival from the time of histologically verified carcinoid tumor was 41 months and from start of therapy 22 months. Our data indicate that combination treatment with streptozocin and 5-fluorouracil is of little value for patients with malignant carcinoid tumors.