Selumetinib Sulfate in Treating Patients With Relapsed or Refractory Advanced Solid Tumors, Non-Hodgkin Lymphoma, or Histiocytic Disorders With Activating MAPK Pathway Mutations (A Pediatric MATCH Treatment Trial)

PRIMARY OBJECTIVE: I. To determine the objective response rate (ORR; complete response + partial response) in pediatric patients treated with selumetinib (AZD6244 hydrogen sulfate) with advanced solid tumors (including central nervous system \[CNS\] tumors), non-Hodgkin lymphomas or histiocytic disorders that harbor activating genetic alterations in the MAPK pathway. SECONDARY OBJECTIVES: I. To estimate the progression free survival in pediatric patients treated with selumetinib (AZD6244 hydrogen sulfate) with advanced solid tumors (including CNS tumors), non-Hodgkin lymphomas or histiocytic disorders that harbor MAPK activation mutations. II. To obtain additional information about the tolerability of selumetinib (AZD6244 hydrogen sulfate) in children with relapsed or refractory cancer. EXPLORATORY OBJECTIVES: I. To evaluate other biomarkers as predictors of response to selumetinib (AZD6244 hydrogen sulfate) and specifically, whether tumors that harbor different mutations or fusions will demonstrate differential response to selumetinib (AZD6244 hydrogen sulfate) treatment. II. To explore approaches to profiling changes in tumor genomics over time through evaluation of circulating tumor deoxyribonucleic acid (DNA). OUTLINE: Patients receive selumetinib sulfate 25 mg/m2/dose orally (PO) twice daily (BID) on days 1-28. Cycles repeat every 28 days for up to 2 years in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up periodically.