title: The polymorphism of CAG repeats in the androgen receptor gene and breast cancer mortality.
abstract: BACKGROUND
  The polymorphic CAG repeats of the androgen receptor (AR) gene have been suggested to affect the risk of breast cancer, but the results are controversial. In addition, the relationship between patients' CAG genotype and the prognosis has not been investigated.
  
  
  OBJECTIVE
  The purpose of this study is to access the association between the polymorphic CAG repeats and the incidence and prognosis of breast cancer.
  
  
  METHODS
  One hundred and fifty-six breast cancer cases and 108 healthy controls from Taipei Veteran General Hospital were enrolled. The length of CAG repeats was analyzed among by means of PCR amplification. The logistic regression model was used for cross-sectional analyses of prevalent breast cancer.Furthermore, we categorized the cases according to the average length of both CAG alleles (CAGn ≥ 23 versus < 23). Outcomes were disease-free survival and mortality. The Cox proportional hazards model and Kaplan-Meier estimate were used for survival analysis.
  
  
  RESULTS
  The median age was 56 (51-64) and 46 (37-52) in breast cancer patients and healthy controls, respectively. The median of CAGn was 22.5 (21.5-24) in study group and 23 (21.5-24) in controls. Our study showed the length of CAG repeats did not contribute to breast cancer or benign breast tumors (HR 1.01; 95% CI, 0.90-1.13). In the median follow-up of 6.59 years, we found the CAGn ≥ 23 (n = 75) could be a poor prognosis (adjust HR, 3.08; 95% CI, 1.42-6.67, p = 0.004).
  
  
  CONCLUSIONS
  The CAG polymorphism is not associated with development of breast cancer, but patients with more CAG repeats of the AR gene are prone to poor prognoses.
authors.affiliation: Department of Medicine, Division of Hematology and Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.|National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Lee
authors.affiliation: Department of Medicine, Division of Transfusion Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Hsueng-Mei
authors.initials: HM
authors.lastname: Liu
authors.affiliation: Department of Medicine, Division of Transfusion Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Li-Hsuan
authors.initials: LH
authors.lastname: Lee
authors.affiliation: Department of Medicine, Division of Hematology and Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.|National Yang-Ming University School of Medicine, Taipei, Taiwan.|Institute of Public Health and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chia-Jen
authors.initials: CJ
authors.lastname: Liu
authors.affiliation: Department of Medicine, Division of Transfusion Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Jeong-Shi
authors.initials: JS
authors.lastname: Lin
authors.affiliation: Department of Medicine, Division of Hematology and Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.|National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Ta-Chung
authors.initials: TC
authors.lastname: Chao
authors.affiliation: Department of Life Science, Fu-Jen University, New Taipei City, Taiwan.
authors.forename: Woan-Fang
authors.initials: WF
authors.lastname: Tzeng
authors.affiliation: Department of Medicine, Division of Transfusion Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Tzeon-Jye
authors.initials: TJ
authors.lastname: Chiou
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D009367:Neoplasm Staging; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011944:Receptors, Androgen / Q000235:genetics*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C410798:AR protein, human; C508053:ERBB2 protein, human
keywords: CAG polymorphism; CAG repeat; Prognostic factor; androgen receptor; breast cancer