When rapidly growing tumors are treated with effective chemotherapy regimens, the dying tumor cells can release large amounts of nucleic acid breakdown products (chiefly uric acid), potassium, phosphate, and lactic acid. The phosphate elevations can lead to hypocalcemia. The increased uric acid, especially in the setting of acidosis, can precipitate in the renal tubules and lead to renal failure. The renal failure can exacerbate the hyperkalemia.
Treatment: Tumor Lysis Syndrome Prevention is the best approach. Maintain hydration with 3 L/d of saline, keep urine pH > 7.0 with bicarbonate administration, and start allopurinol, 300 mg/m2 per day, 24 h before starting chemotherapy. Once chemotherapy is given, monitor serum electrolytes every 6 h. If after 24 h, uric acid (>8 mg/dL) and serum creatinine (>1.6 mg/dL) are elevated, rasburicase (recombinant urate oxidase), 0.2 mg/kg IV daily, may lower uric acid levels. If serum potassium is >6.0 meq/L and renal failure ensues, hemodialysis may be required. Maintain normal calcium levels. |
For a more detailed discussion, see Finberg RW: Infections in Patients with Cancer, Chap. 104, p. 484; Jameson JL, Longo DL: Paraneoplastic Syndromes: Endocrinologic/Hematologic, Chap. 121, p. 608, and Gucalp R, Dutcher J: Oncologic Emergencies, Chap. 331, p. 1787, in HPIM-19. |
Section 2. Medical Emergencies