Background: The aim of this study was to determine the prevalence and outcome of radiation-induced sarcomas (RISs) among sarcoma patients referred to the Norwegian Radium Hospital (NRH).
Material and methods: Ninety patients were identified from the institutional sarcoma data base. Medical records and histological and cytological material from both primary and secondary tumours were reviewed.
Results: RIS represented 3.0 % of the sarcomas in the data base. The median latency time from radiotherapy of the primary tumour to the diagnosis of RIS was 13.6 years (range 2.5-57.8 years). Gynaecological, breast and testicular cancers were the most common primary diagnoses. For the RISs 13 different histological types were identified including 25 malignant fibrous histiocytomas (28% of all) and 22 osteosarcomas (24%). The sarcoma-related 5-year crude survival was 33% (95 % CI 23-43 %). Unfavourable prognostic factors were metastases at presentation, incomplete surgery and presence of tumour necrosis.
Conclusion: Radiation-induced sarcoma is rare and harbours an aggressive clinical behaviour. Complete surgical resection is mandatory for cure.