BACKGROUND/PURPOSE
Tumor lysis syndrome (TLS) occurs when malignant cells rapidly break down. This may lead to hyperuricemia, hyperkalemia, hyperphosphatemia, and/or hypocalcemia. Rasburicase reduces uric acid in cancer patients undergoing anti-cancer therapy. However, caution is required as rasburicase is contraindicated for patients with glucose- 6-phosphate dehydrogenase (G6PD) deficiency due to the increased risk of hemolysis. G6PD deficiency is more prevalent among African Americans (AA), affecting approximately 12% of this population. The FDA recommends testing for G6PD deficiency in higher risk groups before administering rasburicase.
METHODS
A retrospective analysis was conducted at the Louis Stokes Cleveland VAMC from February 1, 2018, to January 31, 2023 addressing appropriate use of rasburicase and incidence of G6PD deficiency and hemolysis. Appropriate use was defined by: TLS (2 or more: uric acid ≥ 8 or 25% increase; K+ ≥ 6.0 or 25% increase; Phos > 4.5mg/dL, or 25% increase; or calcium < 7, or 25% decrease, from baseline) or at high risk for TLS (CLL: venetoclax use w/lymph node > 10cm or WBC > 25k and elevated uric acid; AML: WBC > 100k; ALL: WBC > 100k and LDH 2x ULN; Burkitt lymphoma: LDH 2x ULN).
RESULTS
50 patients were identified who received rasburicase. 21/50 (42%) did not meet criteria for appropriate use. 44/50 (88%) underwent G6PD testing. The average time from G6PD testing order to obtaining the results was 3.4 days; 18/50 patients (36%) had G6PD resulted prior to rasburicase administration, and 26 patients (52%) received rasburicase prior to G6PD results. Overall, 13/50 (26%) were AA. Of the AA pts, 12/13 (92%) were tested for G6PD. Of these 12, 1/12 was found to be G6PD deficient and this patient experienced G6PD deficiency-induced hemolysis after rasburicase. None of the non-AA pts (0/31) tested were found to be G6PD deficient.
IMPLICATIONS
There was a high (42%) level of inappropriate use of rasburicase. G6PD deficiency was uncommon and only found in the AA population. To reduce inappropriate use, rasburicase orders will be restricted to medical oncology. G6PD testing will be limited to AA pts, with pathology to develop a rapid turnaround time for results prior to rasburicase administration to prevent hemolysis.