Osteosarcoma as a second malignant neoplasm

Abstract Purpose : The aim of this study is to compare primary and secondary osteosarcomas using data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program. Methods : Osteosarcoma cases were identified in the SEER Cancer Incidence Public-Use Database, 1973–96 (1511 primary and 133 secondary osteosarcomas). Secondary osteosarcomas were further classified as occurring within or outside the previously irradiated field. Comparisons among groups were performed by nominal logistic regression. Survival analyses were performed using Kaplan–Meir and proportional hazards regression. Results : Secondary osteosarcomas were more likely to have a non-extremity primary site and an older age at diagnosis (>40 years) ( Conclusions : Secondary osteosarcomas are associated with carcinomas especially in the elderly. Although a 50% decreased 5-year survival was observed for secondary osteosarcomas in this study, this might not reflect the current outcomes with more aggressive therapy.