Long-term results with resection of radiation-induced soft tissue sarcomas

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.

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.

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.

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%.