title: Breast cancer risk assessment using genetic variants and risk factors in a Singapore Chinese population.
abstract: BACKGROUND
  Genetic variants for breast cancer risk identified in genome-wide association studies (GWAS) in Western populations require further testing in Asian populations. A risk assessment model incorporating both validated genetic variants and established risk factors may improve its performance in risk prediction of Asian women.
  
  
  METHODS
  A nested case-control study of female breast cancer (411 cases and 1,212 controls) within the Singapore Chinese Health Study was conducted to investigate the effects of 51 genetic variants identified in previous GWAS on breast cancer risk. The independent effect of these genetic variants was assessed by creating a summed genetic risk score (GRS) after adjustment for body mass index and the Gail model risk factors for breast cancer.
  
  
  RESULTS
  The GRS was an independent predictor of breast cancer risk in Chinese women. The multivariate-adjusted odds ratios (95% confidence intervals) of breast cancer for the second, third, and fourth quartiles of the GRS were 1.26 (0.90 to 1.76), 1.47 (1.06 to 2.04) and 1.75 (1.27 to 2.41) respectively (P for trend<0.001). In addition to established risk factors, the GRS improved the classification of 6.2% of women for their absolute risk of breast cancer in the next five years.
  
  
  CONCLUSIONS
  Genetic variants on top of conventional risk factors can improve the risk prediction of breast cancer in Chinese women.
authors.forename: Charmaine Pei Ling
authors.initials: CP
authors.lastname: Lee
authors.forename: Astrid
authors.initials: A
authors.lastname: Irwanto
authors.forename: Agus
authors.initials: A
authors.lastname: Salim
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Yuan
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.forename: Woon Puay
authors.initials: WP
authors.lastname: Koh
authors.forename: Mikael
authors.initials: M
authors.lastname: Hartman
mesh_terms: D000368:Aged; D000483:Alleles; D044466:Asian People; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D016022:Case-Control Studies; D047628:Estrogen Receptor alpha / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha