Tumor Lysis Syndrome

Tumor lysis syndrome (TLS) refers to the laboratory and clinical manifestations resulting from rapid breakdown of high volumes of malignant cells. Significant electrolyte disturbances, particularly hyperuricemia, hyperkalemia, hypocalcemia, and hyperphosphatemia, are hallmarks. Immune dysregulation due to associated cytokine release may occur concurrently, resulting in a systemic inflammatory response. The most significant clinical complications of TLS include cardiac arrhythmias, sudden death, seizures, and renal failure. With the introduction of potent targeted therapies, TLS is now encountered with increasing frequency in diverse oncology patient settings, including diseases previously not considered prone to high TLS risk. Failure to identify and apply preventative strategies to at-risk patients may result in life-threatening complications and premature death. Once established, TLS is a medical emergency that requires acute intervention but is inherently reversible with appropriate supportive measures. In the palliative care setting, patients remain at risk of TLS, and clinicians should be aware of its potential, particularly as the onset may be iatrogenic. This is pertinent in the era of newer novel agents which are increasingly available to those who may not previously have been deemed fit for traditional cytotoxic chemotherapy. Clear communication between clinicians and patients is critical in order to ensure that appropriate interventions are delivered in a timely fashion while considering a patient’s wishes delimiting ceilings of care. This is particularly important given the potential for reversibility of the most critical effects of TLS. This chapter provides an overview of the etiology, symptomatology, and standardized definitions of TLS. We also discuss prevention, management, and special considerations in the palliative care setting.