What is tumor lysis syndrome?
Tumor lysis syndrome (TLS) is a medical emergency. It happens when many cancer cells die at once, releasing substances such as potassium and phosphorus into the blood. The breakdown of cancer cells can also cause uric acid levels to rise. These changes in the blood can cause serious problems with the kidneys, heart, and other organs.
TLS most often happens during the first few days of cancer treatment. It can also happen before treatment starts.
Children at high risk for TLS have frequent blood tests. These tests help the care team find problems early, often before symptoms start.
To help prevent TLS, the care team may give fluids and medicines before and during the start of cancer treatment. If TLS develops, additional treatment may be needed.
Symptoms of tumor lysis syndrome
Many children do not have symptoms of tumor lysis syndrome. If symptoms do occur, they may include:
Many of these symptoms can also be due to other causes. Always tell your care team about new or worsening symptoms.
Risk factors for tumor lysis syndrome
Tumor lysis syndrome is most common in children with fast-growing blood cancers, including:
It can also happen with other types of cancer, including solid tumors. This is less common in children.
Other factors that increase the risk of TLS include:
- A large number of cancer cells in the body
- Cancer that responds quickly to treatment
- High uric acid or phosphorus levels before treatment
- Kidney problems
- Dehydration
Not every child with these risk factors develops TLS. Your child's care team will decide how closely to watch your child based on your child’s health and risk factors.
Diagnosis of tumor lysis syndrome
Tumor lysis syndrome can happen quickly. Doctors use information about your child’s condition and blood chemistry tests to diagnose it.
These tests measure:
- Potassium
- Phosphorus
- Uric acid
- Calcium
- Kidney function (creatinine and blood urea nitrogen)
Common blood test results in tumor lysis syndrome
Doctors also check for symptoms and signs that the kidneys, heart, or other organs may be affected.
Keep all blood test appointments, even if your child feels well. Changes in blood chemistry test results are often the first sign of TLS.
Treatment of tumor lysis syndrome
Children at high risk for tumor lysis syndrome often receive fluids and medicines to help prevent TLS before cancer treatment starts. If TLS develops, additional treatment may be needed to protect the heart and kidneys.
Treatments may include:
- IV (intravenous) fluids to keep your child hydrated and help the kidneys remove waste from the body
- Medicines to prevent or lower high uric acid, such as allopurinol and rasburicase. The medicines your child receives depend on their risk for tumor lysis syndrome and their uric acid levels. Rasburicase should not be given to patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Your care team may test for G6PD deficiency before giving rasburicase.
- Medicines to lower phosphorus, such as phosphate binders like sevelamer, lanthanum, or aluminum hydroxide
- Limiting foods that are high in phosphorus
- Medicines to treat electrolyte changes if potassium, phosphorus, or calcium get too high or too low
- Dialysis if the kidneys cannot remove waste from the blood or if other treatments do not work
Most children recover without long-term problems, especially when tumor lysis syndrome is recognized and treated early.
When to contact your care team
Contact your care team right away if your child has:
- Severe muscle cramps or weakness
- Little or no urine
- Swelling that gets worse
- New symptoms or symptoms that get worse
Call 911 or go to the nearest emergency room right away if your child:
- Has trouble breathing
- Has a seizure
- Is confused or hard to wake up
- Passes out (faints)
Always follow the instructions given by your care team. Talk to your doctor or pharmacist if you have questions or concerns.
Tumor lysis syndrome can become serious quickly. Early diagnosis and treatment help prevent or reduce serious problems.
Questions to ask your care team
