Tumor Lysis Syndrome: Symptoms, Causes, Treatment

What are the symptoms of tumor lysis syndrome?

Tumor lysis syndrome (TLS) is a potentially life-threatening condition that occurs when cancer cells break down rapidly, releasing their contents into the bloodstream. The symptoms of TLS are primarily due to the resulting electrolyte imbalances and kidney dysfunction. Common symptoms include:

Nausea and vomiting: These are often early signs of TLS.
Muscle cramps, twitching, or weakness: Caused by high levels of potassium (hyperkalemia).
Fatigue and lethargy: Due to electrolyte disturbances and kidney issues.
Confusion and agitation: Neurological symptoms can arise from severe imbalances.
Shortness of breath: This may occur due to fluid overload or metabolic abnormalities.
Irregular heartbeat or palpitations: High potassium or low calcium levels can affect the heart’s rhythm.
Seizures: Severe electrolyte disturbances, especially low calcium (hypocalcemia), can trigger seizures.
Decreased urine output or dark urine: Resulting from kidney injury due to the overload of cellular waste.
Swelling and fluid retention: May indicate kidney dysfunction.

TLS typically develops in patients with certain aggressive cancers, especially after the initiation of chemotherapy or other cancer treatments. Early recognition and treatment are essential to prevent serious complications.

What are the causes of tumor lysis syndrome?

Tumor lysis syndrome (TLS) occurs when large numbers of rapidly dividing cancer cells are destroyed, releasing their contents into the bloodstream. The primary causes of TLS include:

Cancer treatments: TLS most commonly occurs after the initiation of chemotherapy, radiation therapy, or other treatments that kill cancer cells quickly. This is especially true for cancers with high cell turnover rates, such as certain leukemias, lymphomas (like Burkitt lymphoma), and other rapidly growing tumors.
Spontaneous tumor lysis: In rare cases, TLS can occur without treatment, especially in cancers with a high burden or those that grow quickly, where cancer cells die and release their contents naturally.
Specific cancer types: Cancers that are more likely to cause TLS include acute leukemias, aggressive non-Hodgkin lymphomas, and other high-grade tumors.

When these cancer cells break down rapidly, they release large amounts of potassium, phosphate, and nucleic acids into the blood. The resulting high levels of these substances lead to:

Hyperkalemia (elevated potassium levels): Can cause dangerous heart rhythms.
Hyperphosphatemia (elevated phosphate levels): Leads to secondary hypocalcemia (low calcium levels) as calcium binds with excess phosphate.
Hyperuricemia (elevated uric acid levels): Formed from the breakdown of nucleic acids, leading to kidney damage due to uric acid crystallization.

The resulting electrolyte imbalances and kidney injury are what cause the life-threatening complications of TLS.

What is the treatment for tumor lysis syndrome?

The treatment for tumor lysis syndrome (TLS) focuses on preventing and managing the complications caused by the rapid release of intracellular contents from dying cancer cells. The main goals are to control electrolyte imbalances, prevent kidney damage, and reduce the risk of life-threatening complications. Treatment typically involves:

1. Hydration and Fluid Management

Aggressive intravenous (IV) hydration is the cornerstone of TLS management. It helps to maintain adequate urine output, flush out excess potassium, phosphate, and uric acid, and prevent kidney damage.
Diuretics (like furosemide) may be used in some cases to promote urine output, but only if the patient is well-hydrated and there’s no risk of dehydration.

2. Management of Electrolyte Imbalances

Hyperkalemia (high potassium levels): Treated with medications like calcium gluconate (to stabilize the heart), insulin with glucose (to shift potassium into cells), and potassium-binding agents.
Hyperphosphatemia (high phosphate levels): Treated with phosphate binders like sevelamer or aluminum hydroxide, and by limiting phosphate intake.
Hypocalcemia (low calcium levels): Treated cautiously because rapid correction can cause further complications. Calcium may be given if severe symptoms (e.g., muscle spasms or heart arrhythmias) are present.

3. Control of Uric Acid Levels

Allopurinol: Prevents the formation of new uric acid by inhibiting xanthine oxidase. It is commonly used as a prophylactic measure.
Rasburicase: Rapidly breaks down uric acid into a more soluble form, making it easier to excrete. It is more effective than allopurinol in high-risk cases or when uric acid levels are already elevated.

4. Dialysis

In severe cases where kidney function deteriorates, or electrolyte imbalances cannot be controlled, dialysis may be required. Hemodialysis can quickly remove excess potassium, phosphate, and uric acid.

5. Monitoring and Supportive Care

Close monitoring in an intensive care setting is often necessary. Continuous monitoring of electrolytes, kidney function, and cardiac rhythm is essential for timely intervention.
Adjustments in cancer treatment might be necessary, such as delaying chemotherapy or altering the regimen.

Early identification and prophylactic measures in high-risk patients can significantly reduce the severity of TLS and improve outcomes.