Background: The purpose of this study was to analyze the effectiveness of radiotherapy for symptomatic, metastatic, and/or unresectable carcinoid tumors.
Methods: From 1975 to 1991, 18 patients with histologically proven carcinoid tumors, including 7 with symptomatic hepatic involvement, received radiotherapy to a total of 31 anatomic sites of metastatic or unresectable carcinoid tumors. Symptomatic response to treatment, date of symptomatic or radiographic progression, and survival after diagnosis and completion of radiotherapy were determined. Clinical improvement was defined as symptomatic relief and/or objective reduction in size of tumor mass sustained for at least 4 weeks.
Results: After radiotherapy of 31 sites in 18 patients, 3 patients died in less than 3 months. Of the remaining 15 patients, survival from initial radiotherapy ranged from 8 to 108 months (median, 23 months), and 8 (53%) died without symptomatic progression in the treated region. Clinical improvement occurred in 27/31 sites (87%). Acute side effects were mild, and no late side effects were recorded. Median survivals from diagnosis were: 39 months for patients with primary tumors of the lung, 33 months for patients with brain metastases, and 32 months for patients with hepatic involvement. Patients with the carcinoid syndrome responded in 19/22 sites (86%) compared with 8/9 sites (89%) for patients without the syndrome (P = not significant).
Conclusions: Radiation therapy can achieve symptomatic palliation for patients with metastatic/unresectable malignant carcinoid tumors, and it is well tolerated. Clinical improvement occurs after irradiation in patients with or without the carcinoid syndrome.