Overall survival trends in pediatric osteosarcoma patients over the past three decades
10041 Background: In the late seventies, the combination of chemotherapy and surgery, significantly improved survival of osteosarcoma patients. However, the chemotherapeutic drugs used for treatment of osteosarcoma patients has not significantly changed since then although surgery clearly improved further and adjuvant chemotherapy have been added. In this study, we retrospectively evaluated, whether after the introduction of neoadjuvant chemotherapy in the late seventies, further improvement in outcome of pediatric osteosarcoma patients was achieved. Methods: Since 1978 and 2008, 54 previously untreated pediatric patients with osteosarcoma were enrolled in six consecutive regimens of different agents and intensity. The main difference between the treatment protocols is the addition of either methothrexate or ifosfamide. Overall survival (OS) and event free survival (EFS) in relationship to the different treatment regimens was calculated using the Kaplan-Meier method. Significance of difference in outcome were calculated using the log rank test. Results: The 5-year EFS and OS of the whole group was 54.7% and 61.1%, respectively. There was no significant difference in outcome in patients treated between 1978 and 1993 (n = 18), as compared to patients treated after 1993 (n = 36, OS 47.1% vs 69.4%, p = 0.34). Of all treatment regimens used, OS was the highest in patients treated with cisplatin, doxorubicin, and methotrexate (OS after 5 year 70%). Multivariate analysis showed that EFS and OS significantly correlated with the histological response but not with one of the treatment regimens used. Conclusions: No significant improvement in overall survival has been accomplished in pediatric osteosarcoma patients during the past thirty years. Histological response after neoadjuvant chemotherapy was the most important prognostic factor. No significant financial relationships to disclose.