Tumor lysis syndrome (TLS)

Patients may be at high risk for developing a condition called “tumor lysis syndrome” (TLS). This condition occurs when many cancer cells die within a short time, releasing their contents into the blood. TLS can be severe during the early phases of treatment, especially for those patients who have very high white blood cell counts before induction therapy.  

TLS can occur after treatment of a fast-growing cancer. As cancer cells die, they break apart and release their contents into the bloodstream, which changes the normal balance of chemicals in the blood. This can overwhelm the kidneys because they cannot filter all of the substances at once. Uric acid is one of the chemicals released by dying cancer cells. Very high levels of uric acid and other chemicals can cause severe damage to the kidneys and heart.  

If untreated, TLS can lead to heart arrhythmias, seizures, loss of muscle control, acute kidney failure, and even death. 

Patients at risk are constantly monitored for the development of TLS and are given drugs such as allopurinol (Zyloprim®) or rasburicase (Elitek®) to prevent or lessen the effects of this condition.