title: Association between CYP2D6 genotypes and the clinical outcomes of adjuvant tamoxifen for breast cancer: a meta-analysis.
abstract: OBJECTIVE
  Tamoxifen is one of the most commonly used endocrine therapeutic agents for breast cancer. Although many studies have examined whether the treatment outcomes of tamoxifen for breast cancer differ according to CYP2D6 genotype, the study results have been inconsistent, and the role of CYP2D6 in the prediction of patient outcomes from tamoxifen therapy remains controversial. This study evaluated the association between CYP2D6 genotypes and postoperative tamoxifen treatment outcome in patients with breast cancer, using the available previous study results.
  
  
  METHODS
  We performed a meta-analysis of ten previous clinical reports (n = 5183) to evaluate the association between CYP2D6 genotype and hazard ratios for the recurrence risk of breast cancer after postoperative tamoxifen treatment. Pooled estimates of hazard ratios were computed using R and NONMEM® software.
  
  
  RESULTS
  A significantly increased risk of breast cancer recurrence in patients carrying variant CYP2D6 genotypes was found in this investigation. The mean hazard ratios and 95% CI were 1.60 (1.04-2.47) in the random effect model implemented in R and 1.63 (1.01-2.62) in the random effect model in NONMEM. The bootstrap result (2000 replicates) of NONMEM was 1.64 (1.07-2.79).
  
  
  CONCLUSIONS
  Our present findings suggest that genetic polymorphisms of CYP2D6 may be important predictors of the clinical outcomes of adjuvant tamoxifen treatment for the patients with breast cancer. A large-scale, prospective, randomized, well-controlled trial is warranted to confirm our findings.
authors: Department of Clinical Pharmacology & Therapeutics, Ulsan University College of Medicine, Asan Medical Center, Pungnap-2-dong, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Republic of Korea.
authors: Jin-A
authors: JA
authors: Jung
authors: Hyeong-Seok
authors: HS
authors: Lim
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000235:genetics; D011379:Prognosis; D013629:Tamoxifen / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D013629:Tamoxifen; D019389:Cytochrome P-450 CYP2D6