Tumour Lysis Syndrome(TLS) (bsh 2015)

3-6% of patients with high grade tumours. 1/3 need dialysis. 15% mortality



Laboratory TLS - ≥2 of the following occurring 3 days prior or 7 days post initiation of treatment for cancer:

  • Uric acid ≥476 umol/l or 25% increase from baseline

  • Potassium ≥6.0 mmol/l or 25% increase from baseline

  • Phosphate ≥1.45 mmol/l (adults) or ≥2.1 mmol/l (children) or 25% increase

  • Calcium ≤1.75 mmol/l or 25% decrease from baseline

Clinical TLS – Laboratory TLS plus at least one of:

  • Creatinine ≥1.5 x the ULN

  • Cardiac arrhythmia

  • Seizure

  • Sudden death



Metabolic syndrome caused by breakdown of malignant cells

Most likely to occur just prior to, or at start of, chemotherapy when disease most active

Excessive release of nucleic acids, proteins and intracellular metabolites from the tumour cells overwhelm the normal homostatic control mechanisms.

  • Hyperkalaemia occurs first and can be life threatening within 6 hours of onset of TLS

  • Uric acid crystals precipitate into the renal tubules, preventing the excretion of the other TLS metabolites. This creates a downward spiral of acute kidney failure.


Risk Factors

High tumour burden

High grade tumour with rapid turnover (e.g. Burkitts, ALL)

Pre-existing renal impairment

Increased age

Use of highly active, cell-cycle specific chemotherapy

Concomitant use of drugs that increase uric acid levels – alcohol, vit C, aspirin, caffeine, cisplatin, thiazides, levodopa, phenothiazines, theophylline.




Allopurinol (Xanthine Oxidase Inhibitor)

  • Reduces production of uric acid by decreasing the rate of conversion of hypoxanthine to xanthine, and of xanthine to allopurinol.

  • Both hypoxanthine and xanthine are more soluble than uric acid and so less precipitation occurs in the renal tubules.

  • Does not increase rate of breakdown of uric acid that is already present so its therapeutic effect is delayed by 24-72 hours.


Rasburicase (Exogenous recombinant urate oxidase)

  • Recombinant form of mammalian urate oxidase. Not found in humans.

  • Metabolises urate to allantoin, a substance 10x more soluble than uric acid.

  • Acts immediately, and on any uric acid that is already formed.

  • Contra-indicated in G6PD deficiency (Risk of oxidative haemolysis)

  • Allopurinol should not be given together as its M.O.A may delay the effect of rasburicase.



Risk Stratification

Low Risk

  • Clinical decision based on lack of risk factors and low tumour burden

Intermediate Risk

  • Not high or low risk

High Risk

  • AML or ALL with WBC >100

  • Burkitts leukaemia / lymphoma or ALL

  • High grade lymphoma with bulky disease (LDH 2x ULN or >10cm on CT)

  • Prior renal impairment or allopurinol allergy



Low Risk

  • Monitoring + 3L/24 hrs Hydration + consider omitting Allopurinol

Intermediate Risk

  • Monitoring + 3L/24 hrs Hydration + 7 days 300mg Allopurinol

High Risk

  • Monitoring + 3L/24 hrs Hydration + single dose 3mg Rasburicase

  • Monitoring bloods must be taken to lab on ice (rasburicase will continue to lower urate level in vitro at room temperature —> falsely reassuring result)




MDT approach with haematology, renal and intensive care

Cardiac monitoring (calcium / potassium)

3L/m2 IV fluids to maintain high urine output >100ml/m2/hour

Rasburicase 0.2mg/kg/day, duration determine by clinical response

Dialysis if fluid overload / electrolytes uncontrolled (furosemide é uric acid deposition)

Hyperphosphataemia – nil specific

Hypocalcaemia – only treat if symptomatic

Hyperkalaemia – usually treatments but short-lived effect, likely need dialysis