As reported to Chris Pirschel by Martha Lassiter, RN, MSN, AOCNS®, BMTCN®
Tumor lysis syndrome (TLS) is an oncologic emergency caused by massive tumor cell death with the release of large amounts of potassium, phosphate, and nucleic acids into systemic circulation. Nucleic acids break down to uric acid, leading to hyperuricemia in patients. This, in turn, leads to precipitates in the renal tubules, renal vasoconstriction, decreased renal flow, inflammation, and can potentially cause acute kidney injury.
The condition is primarily seen in patients who have a clinically aggressive lymphoma (Burkitt subtype) and T-cell acute lymphoblastic leukemia. It can also occur with other tumor types that have a high proliferation rate, large tumor burden, or high sensitivity to cytotoxic therapy.
Prevention is the best treatment for TLS. Educating patients and caregivers about symptoms will help them alert medical staff if signs begin to show. Patients and providers should be aware of the following features and risk factors:
- High tumor cell proliferation rate
- Chemosensitivity of the malignancy
- Bulky tumor burden or elevated white blood cell count (greater than 50,000/microliter)
- Pretreatment elevated serum lactate dehydrogenase (twice the upper limit)
- Organ infiltration
- Bone marrow involvement
- Pretreatment hyperuricemia (more than 7.5 mg/dl) or hyperphosphatemia
- Preexisting nephropathy or exposure to nephrotoxins
- Dehydration, volume depletion, or inadequate hydration during treatment
Clinical symptoms include hyperkalemia, hyperphosphatemia, hypocalcemia, nausea, vomiting, diarrhea, anorexia, lethargy, hematuria, muscle cramps, syncopy, heart failure, and cardiac dysthymias.
Research into preventing TLS is focused on the use of new targeted therapies as single agents or in combination with chemotherapy. This has led to increased frequency and severity of TLS in hematologic cancers that historically had not been identified as an at-risk population. These drugs associated with the increase are venetoclax, obinutuzumab, dinaciclib, and alvocidib.
Allopurinol and rasburicase are currently used for the prevention of TLS. A third agent, oral febuxostat, is a xanthine oxidase inhibitor that is also available. Febuxostat’s advantage over allopurinol is that it doesn’t need to be dose adjusted for kidney injury and has few drug-to-drug interactions. Currently, febuxostat is far more expensive than allopurinol and is not generally recommended except for special circumstances.
Ultimately, being informed about a patient’s diagnosis and risk for TLS is the first step in preventing this potentially dangerous oncologic emergency. Nurses are likely the first to identify symptoms of TLS and are in a unique position to act quickly to prevent long-term adverse reactions. Our institution’s interprofessional team developed a treatment algorithm for patients at high risk of TLS. This treatment order set allows nurses to act quickly when early signs of TLS appear. Through early intervention, patients are less likely to experience long-term organ damage.