Tumor Lysis Syndrome 

Updated: Dec 07, 2018
Author: Alan K Ikeda, MD; Chief Editor: Wafik S El-Deiry, MD, PhD 

Overview

Practice Essentials

Tumor lysis syndrome refers to the constellation of metabolic disturbances that occurs when large numbers of neoplastic cells are killed rapidly, leading to the release of intracellular ions and metabolic byproducts into the systemic circulation.[1] Clinically, the syndrome is characterized by rapid development of hyperuricemia,hyperkalemia, hyperphosphatemia, hypocalcemia, and acute kidney injury.[2, 3] (See Pathophysiology, Etiology, Prognosis, Presentation, and Workup.)

Tumor lysis syndrome arises most commonly after the start of initial chemotherapeutic treatment, but spontaneous cases have increasingly been documented in patients with high-grade hematologic malignancies.[4]

Although tumor lysis syndrome has been reported with virtually every type of tumor, it is typically associated with bulky, rapidly proliferating, treatment-responsive tumors[5] —typically, acute leukemias and high-grade non-Hodgkin lymphomas such as Burkitt lymphoma.[6, 7] The syndrome has also been reported with other hematologic malignancies and with solid tumors such as hepatoblastoma and stage IV neuroblastoma.[8]

Because tumor lysis syndrome is potentially lethal, the main principles of management are (1) identification of high-risk patients with initiation of preventive therapy and (2) early recognition of metabolic and renal complications and the prompt administration of supportive care, including hemodialysis.[9, 10] (See Prognosis, Treatment, and Medication.)

Pathophysiology

Rapid tumor cell turnover results in release of intracellular contents into the circulation. This release can inundate renal elimination and cellular buffering mechanisms, leading to numerous metabolic derangements.

Clinically significant tumor lysis syndrome can occur spontaneously, but it is most often seen 48-72 hours after initiation of cancer treatment. Hyperkalemia is often the earliest laboratory manifestation. Hyperkalemia and hyperphosphatemia result directly from rapid cell lysis.

Hypocalcemia is a consequence of acute hyperphosphatemia with subsequent precipitation of calcium phosphate in soft tissues. In acute kidney injury, decreased calcitriol levels also cause hypocalcemia.

Hyperuricemia

Uric acid is the terminal catabolic product of purine metabolism in humans. Nucleic acid purines, which are released by cell breakdown, are ultimately metabolized to uric acid by hepatic xanthine oxidase. This conversion leads to hyperuricemia.

Uric acid is a weak acid with a pKa of approximately 5.4. It is soluble in plasma and is freely filtered at the renal glomeruli. However, uric acid is less soluble in renal tubular and collecting duct fluid due to normally acidic media, thus increasing the possibility of uric acid crystal formation in cases of hyperuricemia.

Acute kidney injury

The kidney is the primary organ involved in the clearance of uric acid, potassium, and phosphate. Preexisting volume depletion or renal dysfunction predisposes patients to worsening metabolic derangements and acute kidney injury (AKI). The AKI is often oliguric and can be multifactorial in etiology.

Uric acid nephropathy, however, is the major cause of AKI. Its development is due to mechanical obstruction by uric acid crystals in the renal tubules. Uric acid has a pKa of 5.6; uric acid precipitation is enhanced by high acidity and high concentration in the renal tubular fluid, and uric acid becomes less soluble as renal tubule pH decreases. Renal medullary hemoconcentration and decreased tubular flow rate also contribute to crystallization.[11]

Another cause of AKI is acute nephrocalcinosis from calcium phosphate crystal precipitation, which may occur in other tissues. This develops in the setting of hyperphosphatemia and is exacerbated by overzealous iatrogenic alkalinization, because calcium phosphate, unlike uric acid, becomes less soluble at an alkaline pH. Precipitation of xanthine, which is even less soluble in urine than uric acid, or other purine metabolites whose urinary excretion is increased by the use of allopurinol, are other causes of AKI.

Etiology

Tumor lysis syndrome occurs most often in patients with acute leukemia with high white blood cell (WBC) counts and in those with high-grade lymphomas in response to aggressive treatment. Tumor lysis syndrome may also occur in other hematologic malignancies and in a variety of solid tumors such as hepatoblastoma and stage IV neuroblastoma.[8] It has occasionally occurred spontaneously, prior to any form of therapy.[12]

Patients at highest risk are those with bulky, rapidly proliferating tumors that are sensitive to treatment. An elevated pretreatment lactate dehydrogenase (LDH) level, which correlates with high tumor volume, is a strong prognostic indicator for developing clinically significant complications of therapy. The presence of renal insufficiency prior to therapy also correlates with an increased likelihood of tumor lysis syndrome.

An international consensus expert panel has proposed a classification that stratifies cancers into high, intermediate, or low risk for tumor lysis syndrome.[7] The high-risk group of cancers includes the following:

  • Advanced Burkitt lymphoma/leukemia or early-stage disease with elevated baseline LDH
  • Acute lymphocytic leukemia (ALL) with white blood cell (WBC) count ≥ 100,000/µL, or less if the baseline elevation of LDH is twice the upper limit of normal (ULN)
  • Acute myeloid leukemia (AML) with WBC count ≥10000/µL
  • Diffuse large B-cell lymphoma with an elevated baseline LDH of twice ULN and bulky disease

Intermediate-risk malignancies include the following:

  • AML with  WBC of 25,000–100,000/µL
  • ALL with WBC < 100000/µL and an LDH of less than twice ULN
  • Early stage Burkitt lymphoma/leukemia with an LDH of less than twice ULN
  • Diffuse large B-cell lymphoma with a baseline increase in LDH of twice ULN but non-bulky disease

Low-risk diseases include the following:

  • Indolent lymphomas
  • Chronic lymphocytic leukemia
  • Chronic myeloid leukemia in the chronic phase
  • AML with WBC count < 25,000/µL and an LDH elevated to less than twice ULN
  • Multiple myeloma
  • Solid cancers

Reports exist of tumor lysis syndrome associated with the administration of radiation therapy,[13] corticosteroids, hormonal agents, biologic response modifiers, and monoclonal antibodies. Agents reported to cause tumor lysis syndrome include the following:

  • Paclitaxel

  • Fludarabine

  • Etoposide

  • Thalidomide[14]

  • Bortezomib[15]

  • Zoledronic acid[16]

  • Hydroxyurea

The development of tumor lysis syndrome is not limited to the systemic administration of agents; it can occur with intrathecal administration of chemotherapy and with chemo-embolization.

Rare clinical situations in which tumor lysis syndrome has been observed[17] include pregnancy and fever. Patients under general anesthesia have also experienced tumor lysis syndrome.

Epidemiology

International occurrence

The incidence of tumor lysis syndrome is unknown. The prevalence varies among different malignancies; bulky, aggressive, treatment-sensitive tumors are associated with higher frequencies of tumor lysis syndrome. In studies of frequency in patients with intermediate-grade or high-grade non-Hodgkin lymphomas, laboratory evidence of tumor lysis syndrome (42%) occurred much more frequently than the symptomatic clinical syndrome (6%). In children with acute leukemia receiving induction chemotherapy, silent laboratory evidence of tumor lysis syndrome occurred in 70% of cases, but clinically significant tumor lysis syndrome occurred in only 3% of cases.

As advances are made in cancer treatment and as high-dose regimens become more commonplace, tumor lysis syndrome incidence may increase and the syndrome may emerge in a broader spectrum of malignancies.

Age-related demographics

Although tumor lysis syndrome occurs in all age groups, advanced age leading to impaired renal function may predispose patients to clinically significant tumor lysis syndrome owing to a decreased ability to dispose of tumor lysis byproducts.

Prognosis

Early recognition of signs and symptoms of patients at risk for tumor lysis syndrome, including identification of abnormal clinical and laboratory values, can lead to successful prevention of the otherwise life-threatening complications of the condition.

Potential complications of tumor lysis syndrome include uremia and oliguric renal failure due to tubule precipitation of uric acid, calcium phosphate, or hypoxanthine.

Severe electrolyte disturbances, such as hyperkalemia and hypocalcemia, predispose patients to cardiac arrhythmia and seizures.

Iatrogenic complications, such as pulmonary edema from overly vigorous hydration or metabolic alkalosis from excess exogenous administration of bicarbonate, can also occur and are life threatening if not immediately addressed.

Acute kidney injury

Renal tubule precipitation of uric acid, calcium phosphate, or hypoxanthine causes acute kidney injury. This is often oliguric (< 400 mL daily) in nature, leading to volume overload and complications of hypertension and pulmonary edema.

High blood urea nitrogen (BUN) levels due to increased protein catabolism and renal impairment can be severe enough to result in pericarditis, platelet dysfunction, and defective cellular immunity. Renal dysfunction can be severe enough to require dialysis, but with prompt supportive measures, it is usually reversible.

Cardiac arrhythmia

Hyperkalemia can lead to electrocardiographic changes and life-threatening cardiac arrhythmia, including asystole. Severe potassium elevation can cause electrocardiographic alterations such as peaked T waves, flattened P waves, prolonged PR interval, widened QRS complexes, deep S wave, and sine waves. Hypocalcemia can lead to QT interval lengthening, which predisposes patients to ventricular arrhythmia.

Metabolic acidosis

Acute kidney injury and the liberation of large amounts of endogenous intracellular acids from cellular catabolism result in acidemia. This acidemia causes a decrease in serum bicarbonate concentration and a high anion gap acidosis (see the Anion Gap calculator).

Acidemic states can worsen the many electrolyte imbalances already present in tumor lysis syndrome; intracellular uptake of potassium is hindered, uric acid solubility is decreased, and extracellular shift of phosphate is promoted. Calcium phosphate solubility, however, improves in acidic conditions.

The myriad of metabolic disorders must be assessed and treated rapidly. Proper fluid management, alkalinization of the urine, correction of acidosis, and attention to infections are the mainstays of therapy.

 

Presentation

History

In tumor lysis syndrome, a constellation of clinical signs and symptoms may develop prior to the initiation of chemotherapy or, more commonly, within 72 hours after administration of cytotoxic therapy.[18] Inquiries should be made with regard to the following:

  • Time of onset of symptoms of malignancy

  • Presence of abdominal pain and distension

  • Presence of urinary symptoms - Such as dysuria, oliguria, flank pain, and hematuria

  • Occurrence of any symptoms of hypocalcemia - Such as anorexia, vomiting, cramps, seizures, spasms, altered mental status, and tetany

  • Symptoms of hyperkalemia - Such as weakness and paralysis

Other manifestations of tumor lysis syndrome include the following:

  • Lethargy

  • Edema

  • Fluid overload

  • Congestive heart failure

  • Cardiac dysrhythmias

  • Syncope

  • Sudden death

Physical Examination

Symptoms reflect the severity of underlying metabolic abnormalities. Hyperkalemia can cause paresthesia, weakness, and fatal cardiac arrhythmias.

Severe hypocalcemia can lead to the following signs and symptoms:

  • Paresthesia and tetany with positive Chvostek and Trousseau signs

  • Anxiety

  • Carpal and pedal spasms

  • Bronchospasm

  • Seizures

  • Cardiac arrest

Deposition of calcium phosphate in various tissues may be responsible for the following signs and symptoms:

  • Pruritus

  • Gangrenous changes of the skin

  • Iritis

  • Arthritis

Uremia can produce the following signs and symptoms:

  • Fatigue

  • Weakness

  • Malaise

  • Nausea

  • Vomiting

  • Anorexia

  • Metallic taste

  • Hiccups

  • Neuromuscular irritability

  • Difficulty concentrating

  • Pruritus

  • Restless legs

  • Ecchymoses

As uremia progresses, paresthesia and evidence of pericarditis may develop, as well as signs of drug toxicity from medications eliminated by the kidney. Features of volume overload, such as dyspnea, pulmonary rales, edema, and hypertension, may develop.

Elevated uric acid levels may produce lethargy, nausea, and vomiting. Rapidly increasing uric acid levels may lead to arthralgia and renal colic.

 

DDx

Diagnostic Considerations

Patients with cancer are at increased risk of renal failure from etiologies other than tumor lysis syndrome.[19] Prerenal causes include volume depletion from anorexia, vomiting, diarrhea, and bleeding. Pelvic or retroperitoneal masses can lead to kidney failure from postrenal urinary tract obstruction.

Renal parenchymal disorders include the following:

  • Tumor infiltration

  • Myeloma kidney

  • Drug nephrotoxicity from chemotherapeutic agents or antibiotics

  • Radiocontrast nephropathy

  • Vasculitis

  • Cryoglobulinemic glomerulonephritis

The combination of volume depletion, hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia strongly support the diagnosis of tumor lysis syndrome over other causes.

Differential Diagnoses

 

Workup

Approach Considerations

Early recognition of signs and symptoms of patients at risk for tumor lysis syndrome, including identification of abnormal clinical and laboratory values, can lead to successful prevention of the otherwise life-threatening complications of this condition.

In patients with tumor lysis syndrome, a sample of blood obtained by a wide-bore needle or, preferably, an indwelling cannula should be used to obtain a biochemical profile of the patient for monitoring, including of serum sodium, potassium, chloride, and bicarbonate.

Urine pH and output

If hyperuricemia develops, urine alkalinization prevents renal precipitation of uric acid but may increase the risk for nephrocalcinosis. If alkaline diuresis is employed, regular determinations of urine pH should guide the extent of therapy.

Because increased urine flow rates help to inhibit crystal deposition in renal tubules, close monitoring of urine output is necessary to assess adequacy of hydration. Monitoring urine output for signs of oliguric renal failure is also necessary.

Imaging studies

Radiography of the chest is useful to determine the presence of a large tumor (eg. mediastinal mass). Perform ultrasonography or computed tomography (CT) scanning of the abdomen and retroperitoneum immediately if renal failure or mass lesions in the abdomen are present. Intravenous (IV) contrast may be contraindicated in a patient with renal insufficiency.

Cardiac monitoring

Frequent cardiac assessment (electrocardiography [ECG] or continuous cardiac monitoring) is necessary to monitor electrocardiographic changes, which may herald a lethal arrhythmia caused by potassium and calcium disturbances.

Histologic findings

Pathologic studies demonstrate deposits of uric acid within the distal renal tubule lumina, which cause intrarenal hydronephrosis. Uric acid crystals can also be seen within tubular epithelial cells and the medullary microcirculation. Uric acid precipitates may also occur in the renal pelvis and ureters, leading to hydronephrosis and acute renal failure from extrarenal sources.

Blood Chemistry

High-risk patients should have laboratory monitoring (BUN, creatinine, phosphate, uric acid, and calcium levels) prior to therapy and for 48-72 hours after treatment induction. Follow measurements at least three times per day, or more often if evidence of tumor lysis syndrome develops. Lactate dehydrogenase should be checked at least on diagnosis and prior to treatment, as elevated values can reflect the potential for progressing to tumor lysis syndrome with the initiation of chemotherapy.

Most patients with tumor lysis syndrome have laboratory derangements in lactate dehydrogenase, potassium, phosphate, calcium, and uric acid, as well as abnormal renal functions, occurring 1-3 days after chemotherapy initiation. Hyperkalemia is often the first life-threatening abnormality.

 

Treatment

Approach Considerations

Management of tumor lysis syndrome requires the initiation of preventive measures in high-risk patients prior to cancer treatment, as well as the prompt initiation of supportive care for patients who develop acute tumor lysis syndrome during treatment.[20, 21, 22] (Conservative management and prevention of tumor lysis syndrome are similar.) Identify high-risk patients before treatment by assessing the extent of tumor burden, histopathologic findings, and renal function (see Overview/Etiology.)

Patients with evidence of pretreatment acute tumor lysis syndrome should be started immediately on therapy for it. If possible, cancer treatment should be withheld until all parameters are corrected.

Cancer patients with acute manifestations of tumor lysis syndrome or those at high risk should be treated by personnel who are experienced with the condition’s complications and treatment. An oncology unit or intensive care unit (ICU) with readily available, continuous cardiac monitoring and hemodialysis capabilities is the preferred treatment setting.[23]

If basic supportive care measures are ineffective in controlling electrolyte disturbances or renal function, nephrology and critical care consultants should be accessible to assist in further management.

Laboratory turnover time must be rapid so that metabolic derangements can be addressed before life-threatening problems arise.

Diet

Dietary restrictions are highly dependent on the status of the individual patient. However, patients who are not restricted to a nothing-by-mouth diet could theoretically benefit from restriction of intake of foods that contain high levels of potassium, phosphorus, or uric acid.

Consultations

If initial supportive care measures fail to control electrolyte disturbances or renal failure, nephrology and critical care consultations are important for assistance in further management.

Patients with tumor lysis syndrome may need surgical intervention for central venous line placement or for the placement of a dialysis catheter in cases of extreme hyperkalemia or renal failure.

Surveillance

Severe manifestations of tumor lysis syndrome can be prevented only through meticulous laboratory monitoring and careful clinical observation. Necessary cardiac studies include baseline ECG with follow-up studies or continuous cardiac monitoring during treatment. Appropriate renal surveillance and fluid status determinations require baseline and daily weights, regular vital sign checks, and frequent measurements of both fluid intake and urine output.

Patients at high risk and those with evidence of tumor lysis syndrome should have the following levels monitored at least three times daily:

  • Blood urea nitrogen (BUN)
  • Creatinine
  • Uric acid
  • Potassium
  • Calcium
  • Phosphate
  • Lactate dehydrogenase (LDH)

Monitoring should continue for the first 48-72 hours after chemotherapy initiation. Some patients may need to be placed on dialysis prior to the initiation of therapy.

Control of Hyperuricemia

Allopurinol

Allopurinol is a xanthine oxidase inhibitor; it is administered to reduce the conversion of nucleic acid byproducts to uric acid in order to prevent urate nephropathy and subsequent oliguric renal failure.[24] It is usually given orally at 600 mg daily for prophylaxis and 600-900 mg daily (up to a maximum of 500 mg/m2 daily) for treatment of tumor lysis syndrome. Patients unable to take oral medications can be given IV allopurinol.

Adverse effects include mild-to-severe rash, xanthine stone-induced urolithiasis, acute interstitial nephritis, pneumopathy, fever, and eosinophilia. Moreover, the inhibition of uric acid synthesis promotes an increase of xanthine in plasma and the renal system; although reported to be rare, xanthine has the capacity to precipitate in the renal tubules.

Dose reduction is necessary in renal insufficiency or if the medication is given concomitantly with mercaptopurine, 6-thioguanine, or azathioprine (since allopurinol interferes with the metabolism of these agents).

Rasburicase

Rasburicase (recombinant urate oxidase) can be used when uric acid levels cannot be lowered sufficiently by standard approaches.[25, 26, 27, 28] Rasburicase is useful in cases of hyperuricemia and has been shown to be safe and effective in both pediatric and adult patients. It also has a more rapid onset of action than allopurinol.

Humans do not express urate oxidase, which catalyses the conversion of poorly soluble uric acid to soluble allantoin. By converting uric acid to water-soluble metabolites, urate oxidase effectively decreases plasma and urinary uric acid levels.

Unlike allopurinol, uricase does not increase excretion of xanthine and other purine metabolites; therefore, it does not increase tubule crystallization of these compounds.

Rasburicase is administered by intramuscular injection or IV infusion at dosages ranging from 50-100 U/kg daily. It is contraindicated in glucose-6-phosphate dehydrogenase (G6PD) deficiency and pregnancy.

In G6PD deficiency, excess hydrogen peroxide accumulates as rasburicase breaks down uric acid and accelerates catabolism of its precursors xanthine and hypoxanthine; this accumulation places patients at risk for hemolytic anemia and methemoglobinemias.[29, 30] Some authorities recommend screening for G6PD deficiency prior to administration of the drug.

In addition, because humans do not express urate oxidase, rasburicase can potentially elicit an immune response.

Rasburicase is approved by the US Food and Drug Administration (FDA) for the initial management of plasma uric acid levels in pediatric and adult patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anti-cancer therapy expected to result in tumor lysis and hyperuricemia. Rasburicase is indicated only for a single course of treatment.[31] A study by Nauffal in 92 adult patients wtih tumor lysis syndrome found that uric acid levels normalized in 95% of patients after a single 6-mg dose of rasburicase.[32]

Febuxostat

Febuxostat (Uloric) is a novel xanthine oxidase inhibitor that does not appear to have the hypersensitivity profile of allopurinol. In addition, this agent does not require dosing modification for renal impairment.[4] Initial studies suggested that febuxostat is effective and safe for preventing tumor lysis syndrome.[33]

The Febuxostat for Tumor Lysis Syndrome Prevention in Hematologic Malignancies (FLORENCE) trial found that febuxostat provided better control of serum uric acid compared with allopurinol, with comparable renal function preservation and safety profile. In FLORENCE, 346 patients with hematologic malignancies at intermediate to high risk for tumor lysis syndrome were randomized to receive 120 mg of febuxostat or 200-600 mg of allopurinol daily, starting 2 days before induction chemotherapy, for 7-9 days. Mean area under curve for serum uric acid was was 514.0 ± 225.71 mg h/dL for febuxostat versus 708.0 ± 234.42 mg h/dL for allopurinol (P< 0.0001).[34]

In a Japanese phase III trial comparing febuxostat with allopurinol for prevention of thyperuricemia in 100 patients with malignant tumors receiving chemotherapy, febuxostat was no-inferior to allopurinol. No differences in safety outcomes with the either medication was noted.[35]

Febuxostat is much more expensive than allopurinol. However, in patients with renal impairment or hypersensitivity to allopurinol, febuxostat may be a reasonable choice for prophylaxis of tumor lysis syndrome, pending the publication of further clinical trial results.[4]

Hydration

Volume depletion is a major risk factor for tumor lysis syndrome and must be corrected vigorously. Aggressive IV hydration not only helps to correct electrolyte disturbances by diluting extracellular fluid, it also increases intravascular volume. Increased volume enhances renal blood flow, glomerular filtration rate, and urine volume to decrease the concentration of solutes in the distal nephron and medullary microcirculation.

Ideally, IV hydration in high-risk patients should begin 24-48 hours prior to initiation of cancer therapy and continue for 48-72 hours after completion of chemotherapy.

Continuous infusion rates as high as 4-5 L daily (or 3 L/m2 daily), yielding urine volumes of at least 3 L daily, should be given unless the patient's cardiovascular status indicates impending volume overload.

Diuresis

The use of furosemide or mannitol for osmotic diuresis has not proven to be beneficial as front-line therapy. In fact, these modalities may contribute to uric acid or calcium phosphate precipitation in renal tubules in a volume-contracted patient.

Diuretics should be reserved for well-hydrated patients with insufficient diuresis, and furosemide alone should be considered for the normovolemic patient with hyperkalemia or for the patient with evidence of fluid overload.

Urinary alkalinization

The use of isotonic sodium bicarbonate solutions intravenously to promote alkaline diuresis has the potential benefit of solubilizing, and thus minimizing, intratubular precipitation of uric acid. The goal is to increase urinary pH to 7.0 to maximize uric acid solubility in renal tubules and vessels.

Drawbacks to systemic alkaline therapy include magnification of clinical hypocalcemia by shifting ionized calcium to its nonionized form. An increased likelihood of calcium phosphate precipitation in renal tubules is an additional drawback. For these reasons, routine urine alkalinization is controversial, and if it is employed, it must include close monitoring of urinary pH, serum bicarbonate, and uric acid levels to guide therapy and avoid overzealous alkalinization. Consider withdrawing sodium bicarbonate from IV fluid solutions once serum bicarbonate levels reach 30 mEq/L, urinary pH exceeds 7.5, or serum uric acid levels have normalized.

If urinary alkalinization is not achieved with exogenous bicarbonate solutions despite increasing serum bicarbonate levels, IV acetazolamide at doses of 250-500 mg daily (5 mg/kg daily) may be added to decrease proximal tubule bicarbonate reabsorption, thereby increasing urinary pH.

Treatment of Hyperkalemia

Aggressively treat and monitor hyperkalemia. Immediately restrict dietary potassium and remove potassium from IV fluids. Acute treatment modalities include IV infusion of glucose plus insulin to promote redistribution of potassium from the extracellular to the intracellular space, and IV calcium gluconate as cardioprotection for potassium levels greater than 6.5 mmol/L or for patients with electrocardiographic alterations.

IV hydration with alkaline fluid can also increase intracellular uptake of potassium. Potassium-wasting diuretics may be employed with caution since these may worsen renal precipitation in the volume-contracted patient. Long-term therapy, such as oral potassium-exchange resins, should be given immediately because of the transient effectiveness of acute treatment modalities. If these measures fail to control serum potassium, dialysis should be initiated promptly.

Treatment of Hyperphosphatemia and Hypocalcemia

Hyperphosphatemia is managed with oral phosphate binders and the same solution of glucose plus insulin used for the control of hyperkalemia. Hyperphosphatemia may lead to hypocalcemia, which usually resolves as phosphate levels are corrected.

In some cases, depressed serum 1,25-dihydroxycholecalciferol levels contribute to hypocalcemia, and administration of calcitriol may correct calcium levels. Such therapy, however, should not be undertaken until serum phosphate levels have normalized to avoid metastatic calcium phosphate calcifications. As a rule, do not correct hypocalcemia unless evidence of neuromuscular irritability exists, as indicated by a positive Chvostek or Trousseau sign.

Dialysis

If the previously described therapies for the complications of tumor lysis syndrome fail, consider early initiation of dialysis. Dialysis prevents irreversible renal failure and other life-threatening complications. Indications for dialysis include persistent hyperkalemia or hyperphosphatemia despite treatment, volume overload, uremia, symptomatic hypocalcemia, and hyperuricemia.

Hemodialysis is preferred over peritoneal dialysis because of better phosphate and uric acid clearance rates. Continuous hemofiltration also has been used and is effective in correcting electrolyte abnormalities and fluid overload.

Because hyperkalemia can recur after dialysis is initiated and because of the high phosphate burden in some patients with tumor lysis syndrome, electrolyte levels must be monitored frequently and dialysis repeated as needed.

Prevention

The National Comprehensive Cancer Network advises that tumor lysis syndrome is best managed if it is anticipated and treatment is started before initiation of chemotherapy. Treatment centers on the following[9] :

  • Rigorous hydration
  • Management of hyperuricemia
  • Frequent monitoring of electrolytes and aggressive correction of abnormalities

The NCCN recommends allopurinol for first-line treatment and retreatment for hyperuricemia. Allopurinol is begun 2–3 days prior to chemotherapy and continued for 10–14 days

Alternatively, the NCCN recommends rasburicase when allopurinol is ineffective, and for patients with any of the following risk factors:

  • Presence of any high-risk feature
  • Urgent need to initiate therapy in a patient with high-bulk disease
  • Situations where adequate hydration may be difficult or impossible
  • Acute kidney injury

High-risk features for tumor lysis syndrome include the following[9] :

  • Hematologic malignancies strongly associated with tumor lysis syndrome (eg, Burkitt lymphoma, lymphoblastic lymphoma, occasional cases of diffuse large B-cell lymphoma, chronic lymphocytic leukemia)
  • Spontaneous tumor lysis syndrome
  • Elevated white blood cell count
  • Bone marrow involvement
  • Pre-existing hyperuricemia
  • Renal disease or renal involvement by tumor

The NCCN notes that a single dose of 3–6 mg of rasburicase is frequently adequate. Redosing should be individualized.[9]

British guidelines include the following recommendations for prevention of tumor lysis syndrome[10] :

  • Patients due to receive chemotherapy for any hematological malignancy should be assessed for risk of tumor lysis syndrome
  • Low-risk patients can be managed with careful monitoring of fluid status and laboratory results, with a low threshold for recourse to intravenous fluids and consideration of allopurinol therapy
  • Intermediate-risk patients should be offered up to 7 days of allopurinol prophylaxis, along with increased hydration once cancer treatment is initiated, or until risk of tumor lysis syndrome has resolved
  • High-risk patients should be offered prophylaxis with rasburicase, along with increased hydration
  • In patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, do not use rasburicase; treat such patients with fluids and allopurinol and monitor them carefully
  • Urinary alkalinization is not recommended for tumor lysis syndrome prophylaxis

Guideline recommendations on the use of rasburicase for prevention are listed below[10] :

  • Most high-risk adults can be treated with a single fixed dose of 3 mg rasburicase, but this must be followed by careful monitoring of clinical and biochemical parameters, with repeat dosing if required
  • Most high-risk children can be treated with a single dose of 0.2 mg/kg rasburicase, followed by close laboratory and clinical monitoring; use of a fixed dose of 3 mg seems reasonable, but cannot be firmly recommended on the basis of current evidence
  • The addition of allopurinol is unnecessary and has the potential to reduce the effectiveness of rasburicase
  • Urate assays taken while patients are receiving rasburicase must be sent to the laboratory on ice, to prevent falsely low assay results
 

Guidelines

Guidelines Summary

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: B-Cell Lymphomas. Available at https://www.nccn.org/professionals/physician_gls/pdf/b-cell.pdf. Version 3.2017 — March 27, 2017; Accessed: August 13, 2017.

Jones GL, Will A, Jackson GH, Webb NJ, Rule S, British Committee for Standards in Haematology. Guidelines for the management of tumour lysis syndrome in adults and children with haematological malignancies on behalf of the British Committee for Standards in Haematology. Br J Haematol. 2015 Jun. 169 (5):661-71.

 

Medication

Medication Summary

The management of tumor lysis syndrome, other than hydration and alkalinization, necessitates the administration of drugs to correct metabolic disturbances. Use of these medications should be instituted before the start of chemotherapy; the goal is to achieve optimal metabolic stability. Medications can be adjusted after the start of chemotherapy in response to the level of tumor lysis and/or metabolic disturbances.

Allopurinol, a xanthine oxidase inhibitor, reduces the conversion of nucleic acid byproducts to uric acid, in this way preventing urate nephropathy and subsequent oliguric renal failure.[24] An alternative to allopurinol for decreasing uric acid load is rasburicase (urate oxidase), which controls hyperuricemia by converting uric acid to water-soluble allantoin.[25, 26, 27, 28]

Uricosuric Agents

Class Summary

These agents control hyperuricemia and are used to attempt to prevent urate nephropathy and subsequent oliguric renal failure.

Allopurinol inhibits xanthine oxidase, thereby reducing uric acid. The IV form (Aloprim) may be used for patients unable to tolerate oral administration.

Caution is necessary because of the high uric acid concentration in the urine. Andreoli and associates explained some cases of renal failure on the basis of effects of allopurinol in altering purine excretion.[36] In the presence of allopurinol, the excretion of uric acid, xanthine, and hypoxanthine increases several hundred fold, enough to exceed their solubility limit in the renal tubules even at a urinary pH level of 7. Also, at a urinary pH level higher than 7.5, crystallization of hypoxanthine may occur, which necessitates withdrawal of bicarbonate from IV fluids.

Allopurinol (Zyloprim, Aloprim)

Allopurinol inhibits xanthine oxidase, the enzyme that synthesizes uric acid from hypoxanthine and xanthine, thus decreasing production and excretion of uric acid and increasing the levels of more soluble xanthine and hypoxanthine. The drug reduces the synthesis of uric acid without disrupting the biosynthesis of vital purines. Patient response is measured by serum uric acid levels assessed at 48 hours after the initiation of therapy. Dosage adjustments are made as needed.

Rasburicase (Elitek)

Rasburicase is a recombinant form of the enzyme urate oxidase, which oxidizes uric acid to allantoin. It is indicated for the treatment and prophylaxis of severe hyperuricemia associated with the treatment of malignancy. Hyperuricemia causes a precipitant in the kidneys, which leads to acute renal failure. Unlike uric acid, allantoin is soluble and easily excreted by the kidneys. Elimination half-life for rasburicase is 18 hours.

Electrolytes

Class Summary

These agents are used to prevent and treat hyperkalemia and restore electrolyte balance.

Dextrose (D-glucose) plus insulin

Insulin promotes the redistribution of potassium from extracellular to intracellular space. It stimulates the cellular uptake of potassium within 20-30 minutes. Glucose should be administered along with insulin to prevent hypoglycemia. Monitor blood sugar levels frequently.

Diuretics, Loop

Class Summary

These agents should be reserved for well-hydrated patients with insufficient diuresis.

Furosemide (Lasix)

Furosemide increases the excretion of water by interfering with the chloride-binding cotransport system. This, in turn, inhibits sodium and chloride reabsorption in the ascending loop of Henle and the distal renal tubule. Furosemide has not proven to be beneficial as front-line therapy in tumor lysis syndrome. It may contribute to uric acid or calcium phosphate precipitation in renal tubules in volume-contracted patients.

Alkalinizing Agents

Class Summary

These agents may prevent the crystallization of uric acid.

Acetazolamide (Diamox)

Acetazolamide is a carbonic anhydrase inhibitor. It may be added to decrease proximal tubule bicarbonate reabsorption, thereby increasing urinary pH.

Sodium bicarbonate (Neut)

Sodium bicarbonate is used intravenously to alkalinize urine. It promotes alkaline diuresis, with the potential benefits of solubilizing, and thus minimizing, intratubular precipitation of uric acid. The goal is to increase urinary pH to 7 to maximize uric acid solubility in renal tubules and vessels.

Routine urine alkalinization is controversial, and if employed, it must include close monitoring of urinary pH, serum bicarbonate, and uric acid levels. Consider withdrawing sodium bicarbonate from IV solutions once serum bicarbonate levels reach 30 mEq/L, urinary pH is greater than 7.5, or serum uric acid levels have normalized.

Intracellularly, sodium bicarbonate shifts potassium. It may be considered in the treatment of hyperkalemia, even in the absence of metabolic acidosis.

Electrolyte Supplements, Parenteral

Class Summary

Calcium is used to treat arrhythmias due to hyperkalemia or hypocalcemia. Frank or impending renal failure requires additional therapeutic measures. Hyperkalemia is the most common life-threatening emergency. Chemotherapy may have to be discontinued temporarily. The entire potassium intake should be immediately discontinued.

The use of calcium does not lower serum potassium levels. It is primarily used to protect the myocardium from the deleterious effects of hyperkalemia (ie, arrhythmias) by antagonizing the membrane actions of potassium.

Calcium gluconate

Calcium gluconate is used for cardioprotection when potassium levels are greater than 6.5 mmol/L or for patients with electrocardiographic alterations. This agent moderates nerve and muscle performance and facilitates normal cardiac function.

Calcium chloride

Administer IV calcium gluconate or calcium chloride to stabilize myocardial conduction in a patient with cardiac arrhythmias. Calcium also moderates nerve and muscle performance by regulating the action potential excitation threshold. IV calcium is indicated in all cases of severe hyperkalemia (ie, >6 mEq/L), especially when accompanied by electrocardiographic changes.

Calcium chloride contains about 3 times more elemental calcium than an equal volume of calcium gluconate. Therefore, when hyperkalemia is accompanied by hemodynamic compromise, calcium chloride is preferred over calcium gluconate.

The administration of calcium should be accompanied by the use of other therapies that actually help to lower the serum levels of potassium.

Other calcium salts (eg, glubionate, gluceptate) have even less elemental calcium than calcium gluconate and are not generally recommended for the treatment of hyperkalemia.

Antidotes, Other

Class Summary

Sodium polystyrene sulfonate is an exchange resin that can be used to treat mild to moderate hyperkalemia. Each milliequivalent of potassium is exchanged for 1 mEq of sodium. Agents to treat hyperphosphatemia are also used.

Sodium polystyrene sulfonate (Kayexalate, Kalexate, Kionex)

Sodium polystyrene sulfonate is used in the second stage of therapy to reduce total-body potassium. This agent exchanges sodium for potassium and binds it in the gut, primarily in the large intestine. Its onset of action after oral administration is 2-12 hours and is longer when administered rectally.

Aluminum hydroxide (AlternaGEL)

Aluminum hydroxide has been shown to be an effective phosphate binder. Because of their potential for toxicity, however, aluminum salts are not used as first-line therapy.

Sevelamer hydrochloride (Renagel, Renvela)

This is a polymeric phosphate binder for oral administration. It does not contain aluminum; thus, aluminum intoxication is not a concern.

 

Questions & Answers

Overview

What is tumor lysis syndrome (TLS)?

When does tumor lysis syndrome (TLS) arise?

Which tumors are associated with tumor lysis syndrome (TLS)?

What is the approach to management of tumor lysis syndrome (TLS)?

What is the pathophysiology of tumor lysis syndrome (TLS)?

What is the pathogenesis of hyperuricemia in tumor lysis syndrome (TLS)?

What is the pathogenesis of acute kidney injury (AKI) in tumor lysis syndrome (TLS)?

What causes tumor lysis syndrome (TLS)?

Which patients are at the highest risk for tumor lysis syndrome (TLS)?

What is the classification of cancers for the risk of tumor lysis syndrome (TLS)?

Which agents may cause tumor lysis syndrome (TLS)?

Which clinical conditions are rare causes of tumor lysis syndrome (TLS)?

What is the global incidence of tumor lysis syndrome (TLS)?

How does the incidence of tumor lysis syndrome (TLS) vary by age?

How is tumor lysis syndrome (TLS) prevented?

What are potential complications of tumor lysis syndrome (TLS)?

What causes cardiac arrhythmia and seizures in tumor lysis syndrome (TLS)?

What iatrogenic complications may occur with tumor lysis syndrome (TLS)?

What is the prognosis of acute kidney injury (AKI) in tumor lysis syndrome (TLS)?

What is the prognosis of cardiac arrhythmia in tumor lysis syndrome (TLS)?

What is the prognosis of metabolic acidosis in tumor lysis syndrome (TLS)?

Presentation

What should be the focus of clinical history in the evaluation of tumor lysis syndrome (TLS)?

What are manifestations of tumor lysis syndrome?

What are symptoms of hyperkalemia in tumor lysis syndrome (TLS)?

What are the signs and symptoms of severe hypocalcemia in tumor lysis syndrome (TLS)?

What are the signs and symptoms of calcium phosphate deposition in tumor lysis syndrome (TLS)?

What are the signs and symptoms of uremia relative to in tumor lysis syndrome (TLS)?

DDX

What are diagnostic considerations for tumor lysis syndrome (TLS)?

Which renal parenchymal disorders should be considered in the differential diagnoses of tumor lysis syndrome (TLS)?

What etiologic findings help differentiate tumor lysis syndrome (TLS) from other causes of renal failure?

What are the differential diagnoses for Tumor Lysis Syndrome?

Workup

How can patients at risk for tumor lysis syndrome be identified?

What is the role of urine pH and output monitoring in the evaluation of tumor lysis syndrome (TLS)?

What is the role of imaging studies in the workup of tumor lysis syndrome (TLS)?

What is the role of cardiac monitoring in the workup of tumor lysis syndrome (TLS)?

Which histologic findings are characteristic of tumor lysis syndrome (TLS)?

What is the role of blood chemistry in the workup of tumor lysis syndrome (TLS)?

Treatment

How is tumor lysis syndrome (TLS) managed?

What is the role of dietary restrictions in the management of tumor lysis syndrome?

What consultations are recommended for the treatment of tumor lysis syndrome (TLS)?

What is included in surveillance for the prevention of tumor lysis syndrome (SLS)?

What should be monitored on a daily basis in patients with tumor lysis syndrome (TLS)?

What is the role of allopurinol in the management of tumor lysis syndrome (TLS)?

What is the role of rasburicase (recombinant urate oxidase) in the management of tumor lysis syndrome (TLS)?

What is the role of febuxostat (Uloric) in the management of tumor lysis syndrome (TLS)?

How is hydration maintained in the prevention of tumor lysis syndrome (TLS)?

What is the role of diuresis for the treatment of tumor lysis syndrome?

What is the role of alkaline therapy in the treatment of tumor lysis syndrome (TLS)?

How is hyperkalemia managed in tumor lysis syndrome (TLS)?

How are hyperphosphatemia and hypocalcemia managed in tumor lysis syndrome (TLS)?

What is the role of dialysis in the treatment of tumor lysis syndrome (TLS)?

What are the National Comprehensive Cancer Network (NCCN) recommendations for management of tumor lysis syndrome (TLS)?

What are the NCCN recommendations for use of rasburicase in the treatment of tumor lysis syndrome (TLS)?

What are the risk factors for tumor lysis syndrome (TLS)?

What is the NCCN recommended dosage for rasburicase for the treatment of tumor lysis syndrome (TLS)?

What are the British Society for Haematology (BSH) recommendations for prevention of tumor lysis syndrome (TLS)?

What are the British Society for Haematology (BSH) guidelines for the use of rasburicase in the prevention of tumor lysis syndrome (TLS)?

Guidelines

Where can the NCCN treatment guidelines for tumor lysis syndrome (TLS) be found?

Medications

How are medications used in the management of tumor lysis syndrome (TLS)?

Which medications are used in the treatment of tumor lysis syndrome (TLS)?

Which medications in the drug class Antidotes, Other are used in the treatment of Tumor Lysis Syndrome?

Which medications in the drug class Electrolyte Supplements, Parenteral are used in the treatment of Tumor Lysis Syndrome?

Which medications in the drug class Alkalinizing Agents are used in the treatment of Tumor Lysis Syndrome?

Which medications in the drug class Diuretics, Loop are used in the treatment of Tumor Lysis Syndrome?

Which medications in the drug class Electrolytes are used in the treatment of Tumor Lysis Syndrome?

Which medications in the drug class Uricosuric Agents are used in the treatment of Tumor Lysis Syndrome?