Tumor Lysis Syndrome

Tumor Lysis Syndrome (TLS) refers to the metabolic consequences of the break-up of a tumor within the body, generally on account of cytotoxic (i.e. chemotherapeutic) intervention. In other words, when a cancer patient receives treatment, the cancer cells that are killed release their contents into the bloodstream and throw the metabolic state of the blood out of balance. This is characterized by three serious conditions:

Hyperkalemia: This is a build-up of potassium in the blood, or higher-than-normal levels of potassium in the blood.

Hyperphosphatemia: This is a build-up of phosphates in the blood.

Hyperuricemia: This is a build-up of uric acid in the blood

In all cases, it is the role of the kidneys to clear these substances from the blood, which is why kidney failure is a very real concern when coping with TLS.

Risk Factors for TLS

The highest degree of risk for TLS derives from those tumors that are known to grow the fastest, chiefly because they are known to be most susceptible to chemotherapy and similar anti-cancer interventions. These tumors include:

-- Lymphoblastic Lymphoma
-- Burkitt's lymphoma
-- T-cell acute lymphoblastic leukemia

Lower risk tumors include:
-- Low grade lymphomas
-- Small cell carcinomas
-- Breast carcinomas
-- Multiple myelomas

Other risk factors include:

-- Bulky disease
-- Hepatosplenomegaly (the swelling of the liver and the spleen beyond normal size)
-- High leukocyte count
-- Elevated LDH levels (pre-treatment)
-- Elevated levels of uric acid (pre-treatment)
-- Compromised kidney functions
-- Decreased urine output

Treatment strategies

There are several treatment strategies for Tumor Lysis Syndrome, and the subject is far too extensive for the scope of this entry. However, patients should be made aware by their physicians if they are at higher risk of developing TLS following anti-cancer treatment, and if so, what prophylactic measures can be taken to prevent the syndrome from developing in the first place.

Sources

Boyiadzis, Michael M. et al. Hematology-Oncology Therapy. 2007. New York: McGraw Hill, Medical Publishing Division.
PubMed Health: Hyperkalemia
MedlinePlus: Hepatomegaly