Angiosarcoma treated with radiotherapy: impact of tumor type and size on outcome.

Abstract

Angiosarcoma is a rare and highly malignant vascular neoplasm. The purpose of this study was to elucidate the tumor characteristics and evaluate the efficacy of radiotherapy (RT) for angiosarcoma. Thirty patients with angiosarcoma (20 males and 10 females, age range 4-89 years, median 66) who received RT from 1986 to 1999 were enrolled in the study. Twenty-four patients had angiosarcoma of the face and scalp (AFS), and 6 patients had angiosarcomas at other sites. AFS was classified into two categories (according to the macroscopic features): nodular AFS (14 patients) and endophytic AFS (10 patients). The median prescribed irradiation dose was 68 Gy. Surgery had been previously performed in 9 patients, and adjuvant immunotherapy using recombinant interleukin-2 (rIL-2) was combined during and after RT in 20 patients. Univariate analyses and calculation of survival by Kaplan-Meier methods were performed. Local tumor control was obtained in 17 patients (57%). However, 7 (47%) of them developed distant metastases. The median survival time for all patients was 8 months (7 months for AFS), and the 13-year overall survival rate was 25% (20% for AFS). Twenty-one patients died of angiosarcoma, with the cause of death local failure in 7 patients, distant failure in 7, and both in 7. Tumor type and size were found to be significant prognostic factors (p = 0.004 and p = 0.007, respectively), and age, total amount of rIL-2, gender, radiation dose, and surgery were not. Six patients (4 with nodular AFS and 2 with angiosarcoma in other parts) survived >2 years. No patient with endophytic AFS survived >2 years. Ten patients (33%) died of respiratory failure secondary to pulmonary metastases. High-dose rIL-2 administration suppressed the occurrence of distant metastases (p = 0.006). Two patients developed radiation dermatitis (Radiation Therapy Oncology Group Grade 4). RT, combined with complete resection or adjuvant rIL-2 immunotherapy, could be a promising treatment strategy, leading to prolonged survival in patients with angiosarcoma.