title: Variation in genes related to obesity, weight, and weight change and risk of contralateral breast cancer in the WECARE Study population.
abstract: BACKGROUND
  Body mass index (BMI), a known breast cancer risk factor, could influence breast risk through mechanistic pathways related to sex hormones, insulin resistance, chronic inflammation, and altered levels of adipose-derived hormones. Results from studies of the relationship between BMI and second primary breast cancer have been mixed. To explore the relationship between BMI and asynchronous contralateral breast cancer (CBC), we examined whether variants in genes related to obesity, weight, and weight change are associated with CBC risk.
  
  
  METHODS
  Variants in 20 genes [182 single-nucleotide polymorphisms (SNP)] involved in adipose tissue metabolism, energy balance, insulin resistance, and inflammation, as well as those identified through genome-wide association studies (GWAS) of BMI and type II-diabetes were evaluated. We examined the association between variants in these genes and the risk of CBC among Caucasian participants [643 cases with CBC and 1,271 controls with unilateral breast cancer (UBC)] in the population-based Women's Environmental Cancer and Radiation Epidemiology (WECARE) Study using conditional logistic regression.
  
  
  RESULTS
  After adjustment for multiple comparisons, no statistically significant associations between any variant and CBC risk were seen. Stratification by menopausal or estrogen receptor (ER) status did not alter these findings.
  
  
  CONCLUSIONS
  Among women with early-onset disease who survive a first breast cancer diagnosis, there was no association between variation in obesity-related genes and risk of CBC.
  
  
  CONCLUSIONS
  Genetic variants in genes related to obesity are not likely to strongly influence subsequent risk of developing a second primary breast cancer.
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, 307 E 63rd Street, 2nd floor, New York 10065, USA. brooksj@mskcc.org
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Brooks
authors.forename: Leslie
authors.initials: L
authors.lastname: Bernstein
authors.forename: Sharon N
authors.initials: SN
authors.lastname: Teraoka
authors.forename: Julia A
authors.initials: JA
authors.lastname: Knight
authors.forename: Lene
authors.initials: L
authors.lastname: Mellemkjær
authors.forename: Esther M
authors.initials: EM
authors.lastname: John
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Malone
authors.forename: Anne S
authors.initials: AS
authors.lastname: Reiner
authors.forename: Charles F
authors.initials: CF
authors.lastname: Lynch
authors.forename: Patrick
authors.initials: P
authors.lastname: Concannon
authors.forename: Robert W
authors.initials: RW
authors.lastname: Haile
authors.forename: Jonine L
authors.initials: JL
authors.lastname: Bernstein
mesh_terms: D015992:Body Mass Index; D001835:Body Weight / Q000235:genetics*; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D055106:Genome-Wide Association Study; D006801:Humans; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000235:genetics*; D009765:Obesity / Q000453:epidemiology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D014481:United States / Q000453:epidemiology