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Tumor Lysis Syndrome

Tumor lysis syndrome is a group of potentially life-threatening conditions that may happen within hours after cancer treatment. The condition can rapidly become a medical emergency. Treatment is medication and IV hydration. Healthcare providers focus on preventing tumor lysis syndrome before it can happen.

What Is Tumor Lysis Syndrome?

Tumor lysis syndrome (TLS) is a serious complication of cancer treatment. In TLS, dying cancer cells flood your bloodstream with toxic substances, as well as high levels of uric acid, potassium and phosphate. You also have low calcium levels. This condition is a medical emergency because it may cause kidney failure and cardiac arrest.

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Symptoms and Causes

Symptoms of tumor lysis syndrome

Tumor lysis syndrome may develop during treatment or within 12 to 72 hours after you receive treatment. Your care team will check on issues during and right after your treatment. But if you’re recovering at home, get help right away if you have the following symptoms:

  • Nausea and vomiting
  • Shortness of breath
  • Diarrhea
  • Peeing less than usual
  • Weakness and lethargy
  • Blood in your pee
  • Seizures
  • Muscle cramps
  • Fainting
  • Irregular heartbeat
  • Low blood pressure
  • Joint pain

Tumor lysis syndrome causes

Receiving chemotherapy for cancer is the most common cause. But you may develop tumor lysis syndrome if your treatment includes steroids, targeted therapy or immunotherapy.

TLS happens when substances inside dying cancer cells get into your bloodstream and flow into your kidneys. Normally, your kidneys filter and get rid of these substances. When cancer treatment kills lots of cancer cells, your kidneys can’t filter substances fast enough. You then develop the following conditions:

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Who could be affected by this?

Not everyone treated for cancer will develop tumor lysis syndrome. It most often affects people receiving treatment for certain types of cancer that grow quickly, including:

  • Acute lymphoblastic leukemia
  • Aggressive non-Hodgkin lymphoma, including Burkitt lymphoma and diffuse large B-cell lymphoma
  • Acute myeloid leukemia (AML)
  • B-cell acute lymphoblastic leukemia (ALL)
  • Small cell lung cancer
  • Testicular cancer

Risk factors

Some health issues and conditions increase your risk of tumor lysis syndrome. Your cancer care team will take steps to reduce your risk before you receive treatment. Issues that may increase risk include:

  • Dehydration
  • High uric acid levels before treatment
  • High white blood cell count
  • Preexisting kidney issues
  • A large amount of cancer before treatment initiation

Diagnosis and Tests

How doctors diagnose the condition

Healthcare providers diagnose tumor lysis syndrome by checking for changes in your uric acid, phosphorus levels, potassium levels and calcium levels. Providers may use the term “tumor lysis syndrome hallmarks” or “tumor lysis syndrome cardinals.” They’ll do blood tests and imaging tests.

Blood tests

Your care team will do the following blood tests:

Imaging tests

They’ll do imaging tests to look for issues with your kidneys that TLS may cause. Sometimes, you may get a CT scan to determine the amount of cancer you may have.

Other tests

Your care team will do urinalysis to check for abnormalities in your pee and an ECG to look for signs of an irregular heartbeat.

Management and Treatment

How is tumor lysis syndrome treated?

Your cancer care team treats the syndrome conditions with medication, dialysis and diuretics:

  • Medication: You may receive allopurinol (Aloprim®), rasburicase (Elitek®) and sodium bicarbonate. These drugs remove excess uric acid or break up uric acid in your kidneys.
  • Hydration: You’ll receive a large amount of hydration to flush the kidneys of toxins.
  • Dialysis: You may have this treatment if you have severe kidney damage. Dialysis helps remove excess minerals.
  • Diuretics: This makes you pee a lot. Frequent peeing helps remove excess minerals and uric acid.

Outlook / Prognosis

Can people survive tumor lysis syndrome?

Yes, but tumor lysis syndrome can be life-threatening. That’s why your cancer care team will constantly check to see how your body reacts to treatment. Your team will act right away to manage any signs of TLS. The type of cancer you have and your overall health affect the impact that TLS may have. As with all cancer treatments, your care team will explain the risks and side effects of the treatment you’ll receive.

A note from Cleveland Clinic

Cancer treatment can be tough, especially when it works so well that it rapidly kills cancer cells and causes tumor lysis syndrome. Before you start treatment, your cancer care team will let you know if there’s a chance treatment will cause tumor lysis syndrome. If you’re at risk, they’ll take steps to prevent it. Your team will understand if you have questions and concerns. Don’t hesitate to ask if you need more information about what to expect.

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Medically Reviewed

Last reviewed on 10/06/2025.

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