What are the other Names for this Condition? (Also known as/Synonyms)

• TLS (Tumor Lysis Syndrome)

What is Tumor Lysis Syndrome? (Definition/Background Information)

• Tumor Lysis Syndrome (TLS) is an emergency medical condition caused by the sudden rupture of a large number of tumor cells, usually soon after the start of chemotherapy
• The rupture of these tumor cells floods the bloodstream with metabolites and overwhelms the body's ability to automatically regulate their concentrations
• This metabolic disarray can cause a wide variety of signs and symptoms including nausea, vomiting, seizures, hallucinations, and even kidney failure
• Tumor Lysis Syndrome can occur in individuals with any kind of cancer but is more common among those with cancers of the blood (leukemia and lymphoma)
• Treating Tumor Lysis Syndrome includes aggressive hydration, administration of medications, such as Allopurinol and Rasburicase, and dialysis, as needed
• If left untreated Tumor Lysis Syndrome is often fatal, but early recognition and treatment can often help individuals survive/overcome the initial bout of metabolic disarray

Who gets Tumor Lysis Syndrome? (Age and Sex Distribution)

• Tumor Lysis Syndrome (TLS) occurs in approximately 4.8% of all lymphoma patients
• Males and females of all ages are prone to TLS at equal rates
• Individuals of all races and ethnic groups are affected, with no differences in geographic distributions

What are the Risk Factors for Tumor Lysis Syndrome? (Predisposing Factors)

The risk factors for Tumor Lysis Syndrome (TLS) include the following: 

• Cancer types: Patients with leukemia or lymphoma are at a higher risk for TLS
• Tumor types: Patients that have tumors with high rates of cell turn over are also at a greater risk. This means that patients that respond very well to cancer therapy (radiation therapy and chemotherapy), which causes rapid tumor death of tumor cells are higher prone to TLS
• Kidney issues: Being dehydrated or having renal failure before treatment can increase one’s risk
• Type of cancer treatment: Aggressive therapies are known to predispose a patient to TLS

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Tumor Lysis Syndrome? (Etiology)

• Tumor Lysis Syndrome occurs when a large number of tumor cells are destroyed (killed) all at once, and release their contents into the bloodstream
• This is often a complication arising from treatment, and usually manifest 7-14 days after treatment is started
• The intracellular contents spilling out from the dead tumor cells change the body’s blood pH and ion composition too dramatically for the body’s built-in mechanisms to compensate for the rapid change, which if not treated immediately can lead to highly adverse complications, including death (kidney failure)

What are the Signs and Symptoms of Tumor Lysis Syndrome?

The signs and symptoms of Tumor Lysis Syndrome can include all or some of the following and can vary depending on the underlying type of cancer.

• Hyperkalemia: Tumor cell lysis causes the release of large amounts of potassium which can cause heart abnormalities and muscle weaknesses
• Hyperphosphatemia: When the tumor cells lyse, they release large amounts of phosphates that can cause renal failure and seizures
• Hypocalcemia: The large amounts of phosphate released from tumor cells precipitate the calcium found in the body, causing the body’s level of calcium to drop dramatically. This can lead to seizures and potentially fatal heart arrhythmias
• Hyperuricemia: The DNA released from dead tumor cells is processed in the body and eventually turns into uric acid, causing levels in the body to spike. This can lead to renal failure

The signs and symptoms of the underlying malignancy/condition may also be noted.

How is Tumor Lysis Syndrome Diagnosed?

The following tools may be used in diagnosing Tumor Lysis Syndrome (TLS):

• Complete physical examination and medical history evaluation, including evaluation of underlying cancer/tumor/other medical condition, and their treatments
• Assessment of the presenting signs and symptoms

There are two main definitions of Tumor Lysis Syndrome.

• Laboratory Cairo-Bishop definition: To be classified as a laboratory case of TLS, the patient must have a 25% increase in the levels of potassium, phosphate, uric acid, or a 25% decrease in calcium levels in their blood within three days of starting therapy
• Clinical Cairo-Bishop definition: To be classified as a clinical case by the Cairo-Bishop definition, the patient must have a laboratory diagnosis, and additionally either elevated creatine levels, cardiac arrhythmia, seizure, or death
• There is a grading system for individuals with clinical TLS which ranges from zero to five, with zero being the least severe and five being the most severe. The scale is based on the level of creatinine elevation, grade of seizures, and severity of cardiac arrhythmia

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Tumor Lysis Syndrome?

Many of the complications found in Tumor Lysis Syndrome (TLS) stem from the metabolic disturbances caused by the lysis of tumor cells. This can vary significantly depending on the underlying type of cancer. The complications include the following:

• Seizures: The secondary hypocalcemia caused by increased systemic phosphate levels can cause the patient to have seizures
• Nephropathy and acute kidney injury: The buildup of uric acid crystals in the kidneys can lead to decreased kidney function and even kidney failure
• Heart arrhythmias: Individuals with TLS can develop heart arrhythmias due to systemic hypocalcemia

Additionally, complications may arise from the underlying cancer/condition and its treatment.

How is Tumor Lysis Syndrome Treated?

Treatments for Tumor Lysis Syndrome (TLS) center around returning levels of metabolites within the body back to their normal ranges.

• Stimulating diuresis can help flush out the excess metabolites that accumulate in the body during TLS. This means individuals with TLS should be thoroughly hydrated at all times
• Rasburicase is a medication used to flush out excess uric acid and uric acid crystals from the body. It can be used in tandem with the stimulation of diuresis
• Allopurinol can be used to prevent the formation of uric acid crystals
• Hemodialysis can also be used to treat kidney failure caused by hyperphosphatemia and hyperuricemia

Tumor Lysis Syndrome is a serious medical condition. Follow-up visits to the healthcare provider shortly after their discharge from the hospital is very important and highly recommended. Also, the decision to temporarily stop the cancer treatment may be undertaken by the healthcare provider on a case-by-case basis.

How can Tumor Lysis Syndrome be Prevented?

Reducing the risk of Tumor Lysis Syndrome (TLS) involves a course of action very similar to its treatment, and includes steps such as:

• Thorough hydration: Ensuring high daily urine output (roughly 150 mL/day) prevents the buildup of uric acid crystals in the kidneys and other organs
• Treatment with Rasburicase and Allopurinol
• Urinary alkalinization: Alkalizing urine helps turn uric acid crystals into more soluble salts that can be passed through regular urination
• Decreasing dietary phosphate after a bout of TLS may reduce metabolic dysregulation. This can also be supplemented with phosphate binders to inhibit the absorption of phosphates from meals

What is the Prognosis of Tumor Lysis Syndrome? (Outcomes/Resolutions)

Tumor Lysis Syndrome is a medical emergency, and without appropriate treatment, the prognosis is typically poor.

• If left completely untreated TLS is fatal in approximately 15% of the individuals with blood cancers and 36% of the individuals with solid state cancers
• Even with treatment, the prognosis is still relatively poor. While treatments may help an individual survive the initial bout of TLS, acute kidney injury from TLS can preclude further chemotherapy, and increase the individual’s susceptibility to the underlying malignancy

Additional and Relevant Useful Information for Tumor Lysis Syndrome:

• Some individuals may be highly sensitive or allergic to Allopurinol, and should consult with their physician about using it as a treatment or preventative measure
• Rasburicase is immunogenic, and if used more than once may cause the body to host an immune response that can lead to anaphylaxis. Individuals should consult with their physicians about using Rasburicase multiple times