Brief Summary: The purpose of this study is to evaluate the efficacy and feasibility of combination chemotherapy with target agents according to the result of targeted deep sequencing in pediatric patients with relapsed/refractory solid tumor or AML.

Detailed Description: Outcome of pediatric cancer has been improved substantially over the past few decades, but the prognosis of relapsed/refractory pediatric cancer still remains poor. Advances in genomic technologies have improved the ability to detect diverse somatic and germline genomic aberrations of cancer patients, and it has been incorporated in the clinical management of cancer. Samsung Genomic Institute developed a targeted next-generation sequencing (NGS) platform, CancerSCAN™, which can detect clinically significant genomic aberrations of tumors. In this study, tumor samples of refractory/relapsed pediatric cancer patients will be tested with CancerSCAN™ and the patients will receive combination chemotherapy with matched single-targeted agent or multi-targeted receptor tyrosine kinase inhibitor according to the result of CancerSCAN™. I. Relapsed/refractory solid tumor * Perform CancerSCAN™ at enrollment * Conventional chemotherapy (ifosfamide, carboplatin, etoposide) with matched single-targeted agent (axitinib, crizotinib, dasatinib, erlotinib, everolimus, imatinib, pazopanib, ruxolitinib, sorafenib, vandetanib, vemurafenib, or trastuzumab) or multi-targeted receptor tyrosine kinase inhibitor (pazopanib or sorafenib) according to the result of CancerSCAN™ II. Relapsed/refractory AML * Perform CancerSCAN™ at enrollment * Conventional chemotherapy (fludarabine, cytarabine) with matched single-targeted agent (axitinib, crizotinib, dasatinib, erlotinib, everolimus, imatinib, pazopanib, ruxolitinib, sorafenib, vandetanib, vemurafenib, or trastuzumab) or multi-targeted receptor tyrosine kinase inhibitor (pazopanib or sorafenib) according to the result of CancerSCAN™