Tumor lysis syndrome

Tumor lysis syndrome
Specialty	Oncology, hematology

Tumor lysis syndrome (TLS) is a group of metabolic abnormalities that can occur as a complication from the treatment of cancer,^[1] where large amounts of tumor cells are killed off (lysed) from the treatment, releasing their contents into the bloodstream. This occurs most commonly after the treatment of lymphomas and leukemias and in particular when treating non-Hodgkin lymphoma, acute myeloid leukemia, and acute lymphoblastic leukemia.^[2][3] This is a potentially fatal complication^[3] and patients at increased risk for TLS should be closely monitored while receiving chemotherapy and should receive preventive measures and treatments as necessary.^[4] TLS can also occur on its own (while not being treated with chemotherapy) although this is less common.^[4][5]

Tumor lysis syndrome is characterized by high blood potassium (hyperkalemia), high blood phosphate (hyperphosphatemia), low blood calcium (hypocalcemia), high blood uric acid (hyperuricemia), and higher than normal levels of blood urea nitrogen (BUN).^[4] These changes in blood electrolytes and metabolites are a result of the release of cellular contents of dying cells into the bloodstream.^[4] In this respect, TLS is analogous to rhabdomyolysis, with comparable mechanism and blood chemistry effects but with different cause. In TLS, the breakdown occurs after cytotoxic therapy or from cancers with high cell turnover and tumor proliferation rates.^[4] The metabolic abnormalities seen in tumor lysis syndrome can ultimately result in serious complications such as acute uric acid nephropathy, acute kidney failure, seizures, cardiac arrhythmias, and death.^[6][7]