Chapter 2

Background: Treatment of a radiation-induced sarcoma (RIS) remains an unsolved problem. To provide more insight into the disease process, its characteristics, outcome, and potential outcome determinants were defined. Methods: Between 1978 and 2003, 27 patients- 20 females (74%) and seven males (26%) with a median age 44 years (range, 1-73 years) at the time of diagnosis of the primary-developed an RIS after a median interval of 8 years (range, 3-41 years). The histology of the RIS was 10 (37%) undifferentiated high-grade pleomorphic sarcomas, 7 (26%) angiosarcomas, 6 (22%) fibrosarcomas, 2 (7%) osteosarcomas, 1 (4%) pleomorphic rhabdomyosarcoma, and 1 (4%) pleomorphic leiomyosarcoma. Surgical resection was performed in 21 patients: 13 (62%) R0 (microscopically radical), 4 (19%) R1 (microscopically irradical), 2 (9.5%) R2 (macroscopically irradical), and 2 (9.5%) RX (unknown radicality). Six (22%) patients underwent no resection. Results: The 5-year disease-free survival and overall survival rates were 27 % and 30 %, respectively. The local failure rate after R0 resection was 54%. The distant failure rate for the entire group was 41%. Patients with an R0 resection had a significantly better survival rate (P<0.05) than patients with an R1, R2, or no resection. Conclusions: RISs are aggressive malignancies with a high tendency for local recurrence and distant metastases. Previously applied treatment often hampers adequate resection. Therefore, radical surgical resection is the only chance to improve disease-free and overall survival, but it may also have a palliative role. Still, the overall prognosis remains poor. Radiation-induced sarcoma 1