Introduction: Radiation therapy is increasingly used as adjuvant treatment of many childhood and adult malignancies. Radiation-induced sarcoma is a well recognized if uncommon event. The objective of this study is to determine the prevalence and long-term outcome for patients who develop radiation-induced sarcomas.
Methods: From July 1982 to December 2001, 4884 adult patients with sarcoma were admitted and treated at our institution and recorded in a prospective database. There were 123 (2.5%) patients who had radiation-induced soft tissue sarcomas. Survival was determined by Kaplan-Meier analysis. Patient, tumor, and treatment characteristics were tested for their prognostic significance by log rank and the Cox proportional hazards model.
Results: The median interval between radiation and development of sarcoma was 103 (6 to 534) months. In 114 patients with radiation-induced sarcoma who underwent curative resection, the 5-year actuarial survival was 41%, with a median survival of 48 months at a median follow-up of 36 months for survivors. The most common malignancy for which radiation was used was breast cancer (29%), followed by lymphoma (16%) and prostate cancer (15%). Malignant fibrous histiocytoma (23%) was the most common histologic diagnosis, followed by fibrosarcoma (15%) and angiosarcoma (15%). High-grade tumors (n = 85; 79%), age > 60 years (n = 61; 50%), and gross positive resection margin (n = 36; 32%) were predictive of poor sarcoma-specific survival on univariate and multivariate analysis.
Conclusions: The increasing utilization of adjuvant radiation therapy, especially for early-stage breast cancer mandates long-term follow-up to detect radiation-induced sarcoma. Surgical resection remains the primary therapy, but 5-year survival remains approximately 40%.