Makindo Medical Notes

⚠️ Tumour Lysis Syndrome (TLS) is a life-threatening metabolic emergency that can occur during chemotherapy or radiotherapy, particularly in haematological malignancies. Very rarely, it can occur in bulky or rapidly proliferating solid tumours. 🩺 Prompt recognition and treatment are essential to prevent acute kidney injury, arrhythmias, and death.

ℹ️ About

• ⚡ Metabolic complication during cytotoxic therapy
• 🧬 Caused by rapid breakdown of tumour cells → release of intracellular contents
• 🎗️ Classically seen in haematological malignancies (ALL, AML, high-grade lymphomas)

🧬 Aetiology

• 💥 Rapid tumour cell turnover → release of potassium, phosphate, urate → metabolic derangements
• 🧪 Results in hyperkalaemia, hyperphosphataemia, hypocalcaemia, hyperuricaemia

⚠️ Risk Factors

• 📈 High tumour burden, high-grade/rapidly dividing tumours
• 🩺 Pre-existing renal impairment or tumour infiltration of kidneys
• 👵 Older age
• 💊 Treatment with highly active, cell-cycle specific agents
• 🚫 Concomitant use of uric acid–raising drugs (see below)

💊 Drugs to Avoid (increase uric acid)

• 🍺 Alcohol, ascorbic acid, aspirin, caffeine
• 💉 Cisplatin, diazoxide, thiazide diuretics
• 💊 Adrenaline, ethambutol, levodopa, methyldopa, nicotinic acid
• 🧪 Pyrazinamide, phenothiazines, theophylline

🚨 High-Risk Patients

• 🎗️ Burkitt’s / Burkitt’s-like lymphoma
• 🎗️ Lymphoblastic lymphoma
• 🧪 ALL with WCC >100 × 10⁹/L
• 🧪 AML with WCC >100 × 10⁹/L
• 🧪 CML in blast crisis with WCC >100 × 10⁹/L
• 📊 High-grade lymphoma with bulky disease (LDH >2 × ULN or tumour bulk >10 cm)

🩺 Clinical Features

• 🧾 Often overlap with chemo side effects → correlation with labs essential
• ⬇️ Calcium: cramps, tetany, paraesthesias, arrhythmias, heart block, seizures, confusion
• ⬆️ Phosphate: nausea, diarrhoea, lethargy, seizures
• ⬆️ Uric acid: gout, AKI
• ⬆️ Potassium: arrhythmias, muscle weakness (see Hyperkalaemia)

🔎 Investigations

• 📈 Urea & creatinine ↑ → AKI
• 🧪 Hyperuricaemia, hyperkalaemia, hyperphosphataemia, raised LDH
• ⬇️ Hypocalcaemia, reduced eGFR
• ⚡ Diagnostic definition often uses Cairo-Bishop criteria (≥2 lab changes within 3 days before or 7 days after treatment)

🧪 Pathology

• 💥 Tumour cell lysis → release of intracellular ions & nucleic acids → crystallisation of uric acid & calcium phosphate in renal tubules → AKI

🛡️ Prevention

• 💧 Optimise hydration (2–3 L/day; IV fluids should not contain potassium)
• 💊 Allopurinol: 300 mg/day (start 24–48h before chemo, reduce dose if CrCl <20 ml/min)
• 💉 Rasburicase: consider in high-risk patients or deteriorating biochemistry
• 📊 High-risk: hydration + rasburicase prophylaxis

💊 Management

• 💧 Maintain hydration (3–4 L/day IV fluids). Strict fluid balance + hourly urine output + urinary catheter
• ⚖️ Daily weights; treat fluid retention with IV furosemide/mannitol if >3 kg gain
• 💉 Rasburicase for 3–7 days guided by clinical & biochemical response (avoid in G6PD deficiency)
• 🧪 Monitor biochemistry 4-hourly (K, PO₄, Ca, Mg, urea, creatinine, urate) + ECG monitoring
• ⚡ Hypocalcaemia: treat only if symptomatic with IV calcium gluconate (risk of calcium-phosphate precipitation)
• ⬆️ Hyperphosphataemia: may require dialysis if uncontrolled
• 💊 Avoid calcium supplements except if severe neuromuscular irritability

📚 References

• Oxford NSSG: Prevention & Treatment of Tumour Lysis Syndrome