PURPOSE: Up to 30 % of patients undergoing 5-fluorouracil (5FU)-based chemotherapy experience severe toxicity. Dihydropyrimidine dehydrogenase (DPD) deficiency explains 36-61 % of cases. Predicting toxicity is an unmet challenge. Uracil breath test (UraBT) consists of measuring (13)CO2 in exhaled breath after ingestion of 2-(13)C-uracil to evaluate pyrimidine (and 5FU) catabolism. METHODS: We studied 33 gastrointestinal cancer patients previously exposed to 5FU: Thirteen had grade 3-4 and 20, grade 0-1 toxicity. The following tests were used to evaluate pyrimidine catabolism: (1) sequencing of three exons of DPYD; (2) plasma dihydrouracil/uracil ratio (UH2/U); and (3) UraBT. We tested the performance of UraBT to discriminate patients who had grade 0-1 toxicity versus grade 3-4 toxicity and patients with and without proven DPD deficiency. RESULTS: Of the thirteen patients, four grade 3-4 toxicity patients were proved to be DPD-deficient: Three had deleterious mutations (IVS14 + 1G>A in one; single nucleotide polymorphism 2846A>T in two), and one had low UH2/U ratio. Mean delta over baseline in 50 min (DOB50) significantly differed between groups. DOB50≤161.4 discriminated individuals with grade 3-4 versus grade 0-1 toxicity (sensitivity = 61.5 %; specificity = 85 %) and DPD-deficient versus non-DPD-deficient (sensitivity = 75 %; specificity = 85 %). CONCLUSION: UraBT has moderate accuracy in discriminating individuals who manifested severe toxicity from those who had mild or no toxicity to 5FU.
PURPOSE: Up to 30 % of patients undergoing 5-fluorouracil (5FU)-based chemotherapy experience severe toxicity. Dihydropyrimidine dehydrogenase (DPD) deficiency explains 36-61 % of cases. Predicting toxicity is an unmet challenge. Uracil breath test (UraBT) consists of measuring (13)CO2 in exhaled breath after ingestion of 2-(13)C-uracil to evaluate pyrimidine (and 5FU) catabolism. METHODS: We studied 33 gastrointestinal cancerpatients previously exposed to 5FU: Thirteen had grade 3-4 and 20, grade 0-1 toxicity. The following tests were used to evaluate pyrimidine catabolism: (1) sequencing of three exons of DPYD; (2) plasma dihydrouracil/uracil ratio (UH2/U); and (3) UraBT. We tested the performance of UraBT to discriminate patients who had grade 0-1 toxicity versus grade 3-4 toxicity and patients with and without proven DPD deficiency. RESULTS: Of the thirteen patients, four grade 3-4 toxicitypatients were proved to be DPD-deficient: Three had deleterious mutations (IVS14 + 1G>A in one; single nucleotide polymorphism 2846A>T in two), and one had low UH2/U ratio. Mean delta over baseline in 50 min (DOB50) significantly differed between groups. DOB50≤161.4 discriminated individuals with grade 3-4 versus grade 0-1 toxicity (sensitivity = 61.5 %; specificity = 85 %) and DPD-deficient versus non-DPD-deficient (sensitivity = 75 %; specificity = 85 %). CONCLUSION:UraBT has moderate accuracy in discriminating individuals who manifested severe toxicity from those who had mild or no toxicity to 5FU.
Authors: Jan H Beumer; Edward Chu; Carmen Allegra; Yusuke Tanigawara; Gerard Milano; Robert Diasio; Tae Won Kim; Ron H Mathijssen; Li Zhang; Dirk Arnold; Katsuki Muneoka; Narikazu Boku; Markus Joerger Journal: Clin Pharmacol Ther Date: 2018-09-11 Impact factor: 6.875
Authors: Nuala A Helsby; John Duley; Kathryn E Burns; Claire Bonnet; Soo Hee Jeong; Elliott Brenman; Paula Barlow; Katrina Sharples; David Porter; Michael Findlay Journal: Br J Clin Pharmacol Date: 2019-12-12 Impact factor: 4.335
Authors: Jonathan E Knikman; Hans Gelderblom; Jos H Beijnen; Annemieke Cats; Henk-Jan Guchelaar; Linda M Henricks Journal: Clin Pharmacol Ther Date: 2020-11-12 Impact factor: 6.875