Abstract
BACKGROUND: Osteosarcoma (OS) and the Ewing sarcoma family of tumors (ESFT) are the most common primary pediatric bone malignancies. We sought to assess the diagnostic accuracy of initial tumor biopsies in patients with OS or ESFT at a pediatric cancer center. METHODS: All biopsies performed at initial presentation of patients with OS or ESFT at our institution from 2003 to 2012 were retrospectively reviewed. Diagnostic accuracy and incidence of complications were correlated with study variables using logistic regression analysis. RESULTS: One hundred forty-two biopsies were performed in 105 patients (median age 13.4years, range: 1.8-23.0), 104 (73.2%) OS and 38 (27.8%) ESFT. Thirty-one (21.8%) were performed on metastatic sites. Eighty-five (76.6%) of 111 primary site biopsies were open procedures, and 26 were percutaneous (23.4%). Primary site biopsies were successful in 94.1% of open and 73.1% of percutaneous procedures. Odds of obtaining a successful diagnostic specimen were 7.8 times higher with open approach (CI: 1.6-36.8). Metastatic site biopsies were successful in 66.7% of percutaneous and 100% of open and thoracoscopic procedures. CONCLUSION: Biopsy of metastatic sites was equal to primary site in obtaining diagnostic material with the added benefit of accurate staging, with few adverse events and high diagnostic yield.