Tumor Lysis Syndrome: EBM guidelines

Definition: Tumor lysis syndrome (TLS) is characterized by a group of metabolic derangements including hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and uremia.caused by the massive and abrupt release of cellular components into the blood after the rapid lysis of malignant cells. It is observed most frequently in patients with malignancies with high proliferative rate, large tumor burden, or high sensitivity to cytotoxic therapy such as acute lymphoblastic leukemia (ALL) and Burkitt’s lymphoma after the initiation of cytotoxic therapy. Pathogenesis and Clinical Consequences The release of intracellular metabolites, including nucleic acids, proteins, phosphorus, and potassium after the initiation of cytotoxic chemotherapy or cytolytic antibody therapy can overwhelm normal homeostatic mechanisms, potentially leading to hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and uremia. The crystallization of uric acid or calcium phosphate in renal tubules can further result in impaired renal function. Further, the precipitation of calcium can lead to secondary hypocalcemia, which may be either symptomatic or asymptomatic In some cases, TLS can lead to acute renal failure and even death due to uric acid or calcium phosphate precipitation, xanthine crystallization, tumor infiltration in the kidney, tumor-associated obstructive uropathy, drug associated nephrotoxicity, and/or acute sepsis. The relative risk of developing TLS is significantly higher in patients with high uric acid levels (8 mg/dL) and high phosphorus levels.