Tumour Lysis Syndrome

Introduction

Tumour lysis syndrome is an oncologic emergency that is caused by the massive release of breakdown products from malignant cells; results in hyperkalaemia, hyperuricemia, hyperphosphatemia and hypocalcaemia.

  • Renal damage and arrhythymias can follow.
Tumour Lysis Syndrome

NOTE: Tumor lysis syndrome can be either spontaneous or treatment related.



Cairo and Bishop Classification

Cairo and Bishop Classification of Tumour Lysis Syndrome



Risk Factors

The syndrome is more common

  • With some haematological malignancies, e.g. acute leukaemias, non-Hodgkin lymphomas
  • With tumours that have a high proliferative rate, large tumour burden or high sensitivity to the antineoplastic.
  • With the first cycle of chemotherapy (usually occurs within 12-72 hours after administration, although in some cases, it may occur before chemotherapy).
  • In patients with decreased urinary flow, pre-existing hyperuricemia, renal impairment, dehydration or acidic urine.



Prevention

Prevention is important.

  • Aggressive hydration (sometimes with diuretics to maintain urine output) promotes urate and phosphate excretion.
    • Ensuring adequate hydration alone may be appropriate if risk is low.
  • Allopurinol, started before chemotherapy, is given to prevent hyperuricemia in at-risk patients.
    • Rasburicase may be used in those unable to take allopurinol or at high risk of tumour lysis syndrome.
    • However, rasburicase should generally not be given to individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the risk of severe haemolysis.

Purine Metabolism



Treatment

Treatment may include rasburicase (for hyperuricemia), hydration, correction of electrolyte abnormalities and management of renal dysfunction.

  • Allopurinol should be stopped when rasburicase is commenced.

Electrolyte management

  • Hyperkalaemia is an immediate threat and should be treated aggressively.
  • Calcium administration should be restricted in symptomatic patients with hypocalcaemia or hyperkalaemia to prevent risk of metastatic calcification in the setting of hyperphosphatemia.
  • Hyperphosphatemia should be treated with phosphate binders.
  • Patients with persistent electrolyte abnormalities (hyperkalaemia, hyperphosphatemia, and high calcium-phosphate products) and a pronounced decrease in urine output require renal replacement therapy (i.e. dialysis).

NOTE: Urinary alkalinization to promote urate excretion is not recommended because

  • There is a lack of clear evidence demonstrating benefit.
  • There is a risk of metabolic alkalosis, calcium phosphate precipitation and/or formation of urinary xanthine crystals.



External Links

Comments

Post a Comment