Purpose: To identify the prognostic factors and evaluate the impact of chemotherapy regimens on the outcomes of pediatric osteosarcoma of the extremities.
Methods: Patients younger than 18 years and diagnosed with high-grade osteosarcoma of the extremities during the period between January 2004 and December 2011 were included for retrospective analysis. Demographic characteristics and tumor features were compared between nonmetastatic and metastatic patients. Univariate analyses of overall survival (OS) and progression-free survival (PFS) were performed to evaluate the efficacy of various chemotherapy regimens.
Results: A total of 74 patients (58 with nonmetastatic and 16 with metastatic disease) were enrolled and treated with three protocols consisting of various cycles of high-dose methotrexate, adriamycin (doxorubicin), cisplatin, and high-dose ifosfamide (MACI regimens) during the 8-year study period. Presence of metastasis was inversely correlated with OS and PFS. Alkaline phosphatase levels at diagnosis and histologic response to preoperative chemotherapy were correlated with OS. Tumor size was correlated with PFS. The 5-year OS and PFS were 77 and 70 % for all patients, and 90.4 and 83.3 % for those with nonmetastatic osteosarcoma; and the rates were both 25 % in those with metastatic osteosarcoma. The chemotherapy regimens increased good response rates by 30 % and survival rates by 20 % compared to the outcomes in patients treated before 2004.
Conclusions: Poor prognostic factors for osteosarcoma in pediatric patients were identified under homogeneous surgical and chemotherapy schemes. The four-drug regimens consisting of MACI contributed to the remarkably increased good response rates and consequent improvement in the survival rates.