Treatment and outcome of radiation-induced soft-tissue sarcomas at a specialist institution

Abstract

Background Radiation-induced sarcoma (RIS) is a rare late complication of therapeutic irradiation with a reputation for aggressive pathology and poor outcome. Methods We retrospectively reviewed histopathological features, surgery and outcome in 67 patients with RIS treated between 1990 and 2005 at a single tertiary referral center. Results Previous breast cancer was the most common indication for radiotherapy. The median interval from irradiation to development of RIS of was 11 years (3–36 years). Median tumour size was 7 cm with 56% classified as high grade, 31% intermediate grade and 13% low grade. The commonest histology was leiomyosarcoma. The only relationship for histology with site was for angiosarcoma ( n = 9), all of which developed on the chest wall/breast after irradiation for breast cancer. Of 67 patients, 34 underwent potentially curative surgery, and microscopically clear margins were achieved in 75% of cases. Pedicled or free tissue transfer was required in 12 patients and abdominal or chest wall mesh reconstructions were required in 8 patients. No patient received adjuvant radiotherapy but 7 received adjuvant/neoadjuvant chemotherapy. Median follow up is 53 months. Median sarcoma specific survival was 54 months (2- & 5-year survival: 75% & 45%). The local relapse rate was 65%. Negative histopathological margins were a significant predictor of sarcoma specific survival (HR 3.0 95% CI 1.1–8.6 p = 0.04). Grade and size of tumour approached, but did not attain significance. Conclusion RIS is a biologically aggressive tumour with high rates of local relapse despite aggressive attempts at curative surgery.