The Tumor Lysis Syndrome

The tumor lysis syndrome is the most common disease-related emergency encountered by physicians caring for children or adults with hematologic cancers. 1-4 Although it develops most often in patients with non-Hodgkin's lymphoma or acute leukemia, its frequency is increasing among patients who have tumors that used to be only rarely associated with this complication. 5-8 The tumor lysis syndrome occurs when tumor cells release their contents into the bloodstream, either spontaneously or in response to therapy, leading to the characteristic findings of hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia.(1-3) These electrolyte and metabolic disturbances can progress to clinical toxic effects, including renal insufficiency, cardiac arrhythmias, seizures, and death due to multiorgan failure. Although optimal methods of risk classification and treatment have been difficult to define, uniform standards for management of the tumor lysis syndrome are beginning to evolve. Indeed, several groups have advocated guidelines for risk stratification and made recommendations for evaluating risk and for prophylactic therapy for the tumor lysis syndrome. 2,9 This review of the tumor lysis syndrome summarizes current strategies for risk assessment, prophylaxis, and therapy. The following case illustrates the clinical challenges.