title: Strong association of a common dihydropyrimidine dehydrogenase gene polymorphism with fluoropyrimidine-related toxicity in cancer patients.
abstract: BACKGROUND
  Cancer patients carrying mutations in the dihydropyrimidine dehydrogenase gene (DPYD) have a high risk to experience severe drug-adverse effects following chemotherapy with fluoropyrimidine drugs such as 5-fluorouracil (5-FU) or capecitabine. The pretreatment detection of this impairment of pyrimidine catabolism could prevent serious, potentially lethal side effects. As known deleterious mutations explain only a limited proportion of the drug-adverse events, we systematically searched for additional DPYD variations associated with enhanced drug toxicity.
  
  
  RESULTS
  We performed a whole gene approach covering the entire coding region and compared DPYD genotype frequencies between cancer patients with good (n = 89) and with poor (n = 39) tolerance of a fluoropyrimidine-based chemotherapy regimen. Applying logistic regression analysis and sliding window approaches we identified the strongest association with fluoropyrimidine-related grade III and IV toxicity for the non-synonymous polymorphism c.496A>G (p.Met166Val). We then confirmed our initial results using an independent sample of 53 individuals suffering from drug-adverse-effects. The combined odds ratio calculated for 92 toxicity cases was 4.42 [95% CI 2.12-9.23]; p (trend)<0.001; p (corrected) = 0.001; the attributable risk was 56.9%. Comparing tumor-type matched sets of samples, correlation of c.496A>G with toxicity was particularly present in patients with gastroesophageal and breast cancer, but did not reach significance in patients with colorectal malignancies.
  
  
  CONCLUSIONS
  Our results show compelling evidence that, at least in distinct tumor types, a common DPYD polymorphism strongly contributes to the occurrence of fluoropyrimidine-related drug adverse effects. Carriers of this variant could benefit from individual dose adjustment of the fluoropyrimidine drug or alternate therapies.
authors.affiliation: Department of Gynecology, Klinikum rechts der Isar, Technische Universität München, München, Germany. eva.gross@lrz.tum.de
authors.forename: Eva
authors.initials: E
authors.lastname: Gross
authors.forename: Birgit
authors.initials: B
authors.lastname: Busse
authors.forename: Matthias
authors.initials: M
authors.lastname: Riemenschneider
authors.forename: Steffi
authors.initials: S
authors.lastname: Neubauer
authors.forename: Katharina
authors.initials: K
authors.lastname: Seck
authors.forename: Hanns-Georg
authors.initials: HG
authors.lastname: Klein
authors.forename: Marion
authors.initials: M
authors.lastname: Kiechle
authors.forename: Florian
authors.initials: F
authors.lastname: Lordick
authors.forename: Alfons
authors.initials: A
authors.lastname: Meindl
mesh_terms: D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects* / Q000627:therapeutic use; D016022:Case-Control Studies; D015331:Cohort Studies; D042943:Dihydrouracil Dehydrogenase (NADP) / Q000235:genetics*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000235:genetics*; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D005787:Gene Frequency; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000502:physiology
chemical_list: D000964:Antimetabolites, Antineoplastic; D042943:Dihydrouracil Dehydrogenase (NADP); D005472:Fluorouracil