Impact of single nucleotide polymorphisms of cytarabine metabolic genes on drug toxicity in childhood acute lymphoblastic leukemia

Background Cytarabine (cytosine arabinoside, ara-C) is a chemotherapeutical agent used in the treatment of pediatric acute lymphoblastic leukemia (ALL). Adverse drug reactions, such as interpatient variability in sensitivity to ara-C, are considerable and may cause difficulties during chemotherapy. Single nucleotide polymorphisms (SNPs) can play a significant role in modifying nucleoside-drug pharmacokinetics and pharmacodynamics and thus the development of adverse effects. Our aim was to determine whether polymorphisms in genes encoding transporters and enzymes responsible for the metabolism of ara-C are associated with toxicity and clinical outcome in a patient population with childhood ALL. Procedure We studied 8 SNPs in the CDA, DCK, DCTD, SLC28A3, and SLC29A1 genes in 144 patients with childhood acute lymphoblastic leukemia treated according to ALLIC BFM 1990, 1995 and 2002 protocols. Results DCK rs12648166 and DCK rs4694362 SNPs were associated with hematologic toxicity (OR = 2.63, CI 95% = 1.37–5.04, P = 0.0036 and OR = 2.53, CI 95% = 1.34–4.80, P = 0.0044, respectively). Conclusions Our results indicate that DCK polymorphisms might be important genetic risk factors for hematologic toxicity during ALL treatment with ara-C. Individualized chemotherapy based on genetic profiling may help to optimize ara-C dosing, leading to improvements in clinical outcome and reduced toxicity. Pediatr Blood Cancer 2015;62:622–628. © 2015 Wiley Periodicals, Inc.