Treatment results of children with osteosarcoma according to protocols «Osteosarcoma 2006» and «Osteosarcoma 2014»: experience of pediatric hematology and oncology research institute of N.N. Blokhin russian cancer research center

Background/Objectives. During the last 30 years treatment results of children with osteosarcoma according to different international trials were analyzed. 5years overall survival (OS) of children with localized osteosarcoma was near 75%, 5years eventfree survival (EFS) – 62%, with primary metastatic osteosarcoma – 35% and 25% respectively. In this article we presented results of two pediatric clinical protocols «Osteosarcoma 2006» and «Osteosarcoma 2014».
Design/Methods. From 2009 to 2017 years 221 patients (less than 18 years old age group) with primary diagnosed osteosarcoma were included in trials. 128 patients were treated according to «Osteosarcoma 2006» protocol and 93 – «Osteosarcoma 2014».
Results. Received data showed appropriateness of neoadjuvant chemotherapy in alternating regimen. Higher OS and EFS rates were revealed in children with localized osteosarcoma (р=0,001; р=0,001), good response (grade III and IV of tumor cells necrosis rate) to neoadjuvant chemotherapy after surgery of the primary site (р=0,001; р=0,001). Lung metastases quantity (single or multiple) also determined prognosis of disease (p=0,032). Surgery treatment of lung metastases increased OS and EFS rates (p=0,001; p=0,001).
Conclusion. OS and EFS of patients who treated according to «Osteosarcoma 2006» and «Osteosarcoma 2014» protocols were compared with international trials. Long-term treatment experience of children with osteosarcoma, absence of results improvement open the way to development of new protocols according to molecular-biological tumor features, that determined drug resistance, invasive and metastatic tumor activity, prognosis of disease.