Rasburicase for the prevention and treatment of hyperuricemia in tumor lysis syndrome

PURPOSE: To review current knowledge about tumor lysis syndrome (TLS), a set of metabolic imbalances, including hyperuricemia, that often occur during chemotherapeutic or biotherapeutic treatment of patients with hematologic malignancies. DATA SOURCE: English language journal articles indexed in PubMed. STUDY SELECTION: Recent reviews and original research articles related to TLS, hyperuricemia, and treatment of hyperuricemia were selected for inclusion. RESULTS: The incidence of TLS depends highly on the type of malignancy, its growth characteristics, and the total tumor burden. Patients are at heightened risk if they have hyperuricemia, hypovolemia, or poor renal function before anticancer therapy begins. Recently published guidelines make risk assessment and patient staging more systematic. Prophylactic measures should be used to reduce the risk for TLS in vulnerable patients. Such measures include hydration to facilitate urinary excretion and administration of allopurinol to prevent de novo production of uric acid. If hyperuricemia occurs despite preventative efforts, uric acid concentrations can be reduced with rasburicase, a recombinant, intravenously administered urate oxidase. The cost of rasburicase therapy is substantial but is considerably less than that of hemodialysis and extended hospitalization. Shorter courses or smaller doses of rasburicase than those recommended may be effective in reducing hyperuricemia in some patients, but it is important to recognize that the alternative dosing still awaits validation. CONCLUSIONS: Allopurinol and rasburicase are recommended for preventing hyperuricemia in patients at intermediate or high risk for TLS, respectively. If hyperuricemia develops despite preventative measures, rasburicase treatment is an effective method for lowering uric acid concentrations within normal limits.