Endocrine and Metabolic Symptoms of Cancer and Its Treatment

Abstract

Tumor Lysis Syndrome (TLS), a potentially life-threatening complication for patients with cancer, has been subclassified into either laboratory TLS or clinical TLS. Laboratory TLS is characterized by the rapid development of two or more of the following abnormalities – hyperuricemia, hyperkalemia, hyperphospatemia, hypocalcemia, and azotemia – which occur in cancer patients most often 28–72 h after the initiation of chemotherapy or radiation; however, spontaneous cases have been reported [1]. Clinical manifestations of TLS include renal failure (glomerular filtration rate ≤60 ml/min) and organ damage leading to cardiac arrhythmias or seizures. Predisposing factors for TLS include neoplasms with high growth rates, patients with a large tumor size or burden, high white blood cell count (>50,000/mm3), cancers highly sensitive to chemotherapy or radiation, and patients with extensive bone marrow involvement [2]. Comorbidities that increase the risk for developing TLS include elevated uric acid level prior to treatment, preexisting renal insufficiency, obstructive uropathy, and advanced age [2]. Patients with hematological malignancies including high-grade lymphomas (i.e., Burkitt’s lymphoma) and acute or chronic leukemias are more likely to have complications of TLS. In adults with solid tumors, TLS is a rare complication in chemosensitive tumors including bulky small cell lung cancer and metastatic germ cell carcinoma. In children, TLS is more frequently associated with malignancies that have an increased proliferative fraction, large tumor burden, widely metastatic disease, or increased sensitivity to chemotherapy.