VEGFA and neoplasm: Because of the lack of any definitive evidence of superiority of one regimen over the other in osteosarcoma, oncologists use HDMTX-based or non-HDMTX–based regimens depending on institutional practices and availability.5,6 Chemotherapy response, metastasis, and tumor size and site are reported to be independent prognostic factors of osteosarcoma.17 In addition, it has been suggested that vascular endothelial growth factor expression, dynamic contrast-enhanced magnetic resonance imaging, and positron emission tomography–computed tomography parameters are associated with prognosis.18-20