From the Guidelines
Tumor lysis syndrome (TLS) is a potentially life-threatening metabolic emergency that occurs when large numbers of cancer cells die rapidly, releasing their contents into the bloodstream, and is characterized by hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. This typically happens after initiating chemotherapy for cancers with high cell turnover rates, particularly hematologic malignancies like high-grade lymphomas and leukemias, as noted in studies such as 1 and 1. The syndrome is caused by the release of intracellular contents, including potassium, phosphate, and nucleic acids, which overwhelm the body's normal excretory mechanisms, leading to the characteristic metabolic derangements, as explained in 1.
Key Characteristics and Complications
- Hyperuricemia (elevated uric acid)
- Hyperkalemia (high potassium)
- Hyperphosphatemia (high phosphate)
- Hypocalcemia (low calcium) These imbalances can lead to serious complications, including:
- Acute kidney injury
- Cardiac arrhythmias
- Seizures
- Death if not promptly treated, as highlighted in 1 and 1.
Prevention and Treatment
Prevention and treatment of TLS involve:
- Aggressive hydration with intravenous fluids (2-3 L/day)
- Administration of allopurinol (300-600 mg daily) or rasburicase (0.1-0.2 mg/kg) to reduce uric acid levels, as recommended in 1
- Correction of electrolyte abnormalities
- Sometimes dialysis in severe cases, as noted in 1 and 1. Patients at high risk should begin preventive measures 24-48 hours before starting cancer therapy, as emphasized in 1 and 1.
Pathogenesis
The syndrome develops because dying cancer cells release intracellular contents, including potassium, phosphate, and nucleic acids (which metabolize to uric acid), overwhelming the body's normal excretory mechanisms and leading to the characteristic metabolic derangements, as explained in 1. The release and subsequent catabolism of nucleic acids can result in hyperuricemia, and the precipitation of uric acid in the renal tubules may lead to renal insufficiency or failure, as discussed in 1.
From the FDA Drug Label
Tumor Lysis Syndrome (TLS) Clinical TLS was defined by changes in at least two or more laboratory parameters for hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia and at least one of the following events occurring within 7 days of treatment: renal failure/injury, need for renal dialysis, and/or serum creatinine increase >1.5 ULN, arrhythmia or seizure.
Tumor Lysis Syndrome (TLS) is a condition characterized by changes in laboratory parameters such as hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia, along with events like renal failure, need for renal dialysis, serum creatinine increase, arrhythmia, or seizure.
- Key features of TLS include:
- Changes in at least two laboratory parameters
- At least one of the specified events occurring within 7 days of treatment 2
From the Research
Definition and Characteristics of Tumor Lysis Syndrome
- Tumor lysis syndrome (TLS) is an acute, life-threatening disease that occurs among adults and children, associated with the initiation of cytoreductive therapy in the treatment of malignancy 3.
- It is characterized by a pattern of metabolic derangements resulting from the massive release of intracellular contents into the systemic circulation 3.
- Characteristic findings include hyperuricemia, hyperphosphatemia, hyperkalemia, hypocalcemia, and uremia, which can lead to cardiac arrhythmia, seizures, renal failure, and sudden death 3, 4.
Clinical Presentation and Pathophysiology
- Clinical presentation is characterized by hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia 4.
- Acute kidney injury due to tumor lysis is potentiated by the precipitation of uric acid and calcium phosphate, as well as renal vasoconstriction 4.
- The incidence of TLS appears to be increasing due to the growing use of highly effective biologic and targeted therapies 3.
Management and Prevention
- Risk assessment and prevention are crucial in the management of TLS, relying on clinician awareness, prophylactic measures, and vigilant laboratory monitoring 3.
- Established TLS requires early, aggressive intervention with intravenous hydration, electrolyte management, and the use of hypouricemic agents 3.
- Management may also include medications targeting hyperuricemia, such as rasburicase and allopurinol, and in severe cases, renal replacement therapy may be required 4.